Affected versions of MISP permit unauthenticated or weakly constrained request paths to perform persistent work without adequate input bounds or rate limiting.

The users/forgot password-reset endpoint accepted an attacker-controlled email value without first imposing a reasonable length bound or validating its format. That value was then used to create an audit log entry and queue a password-reset job, causing the supplied value to be persisted more than once per request. The commit explicitly states that an unbounded unauthenticated request field was stored twice per call with no throttle.

The fix adds:

- a maximum email input length of 1024 bytes;  - email-format validation before persistent work;  - a per-source pre-authentication request budget;  - HTTP 429 responses when that budget is exceeded;  - a 15-minute cooldown for API-access request emails;  - POST-only handling and CSRF protection for the API-access request endpoint.

The new flood filter is specifically intended to limit persistent storage costs from anonymous requests such as password resets, registrations, and failed REST authentication attempts.

Version affected: ≤2.5.45

Affected versions of MISP allow authenticated users to retrieve object-reference records by UUID through EventGraphTool::getreferencedata() without first checking whether the requester is authorized to view the object the reference belongs to.

The vulnerable code queried ObjectReference.uuid directly and returned the matching row whenever it existed. Because no parent-object ACL was applied, a user who knew or obtained a reference UUID could retrieve information associated with an object outside their normal access scope. The commit explicitly states that any object reference could be returned by UUID without authorizing its parent object.

The fix retrieves the referenced object's objectid and calls fetchObjectSimple() with the current user. If the user cannot access that parent object, MISP now returns NotFoundException instead of exposing the reference.

Version affected: ≤2.5.45

Affected versions of MISP contain inconsistent authorization checks across dashboard widgets that display organisation information.

Several organisation-related widgets did not honor Security.hideorganisationindexfromusers. As a result, authenticated users without the permsharinggroup permission could enumerate organisations even though the normal organisation index was intentionally hidden from them.

The affected widgets included paths that:

returned organisation names and identifiers;

could expose additional organisation database fields through JSON export because unrestricted find('all') queries fetched full rows;

accepted limit=0 or negative values in a way that could effectively remove the result limit and return the entire organisation table.

A related organisation-contributor leaderboard also ignored the same visibility setting. Its handler counted Event.orgcid across the entire event table and mapped those IDs to organisation names, revealing every organisation with events regardless of whether the caller could see any of those events. The fix withdraws this widget entirely for users who lack organisation-index visibility.

Version affected: ≤2.5.45

Affected versions of MISP insufficiently validate URLs used by dashboard widgets, particularly the Button widget.

The widget's URL is stored configuration controlled by a user. The previous renderer considered a URL safe if it appeared relative or if its parsed hostname matched the configured MISP hostname. That logic failed to reject dangerous schemes and URL forms that browsers normalize differently from PHP's URL parsing.

As a result, values such as javascript: URLs or backslash-based authority forms could reach the generated anchor's href and execute script or navigate to an attacker-controlled origin when another user interacted with the widget. The upstream commit describes the issue as:

“javascript: and backslash URLs reached the href (stored XSS)”.

The fix routes widget URLs through a shared DashboardURLValidator, rejects dangerous schemes, raw backslashes, control characters, and unauthorized absolute origins, and validates the URL both in the widget handler and renderer.

Version affected: ≤2.5.45

Affected versions of MISP contain insufficient validation of server-side outbound HTTP destinations in feed retrieval and TAXII discovery functionality.

In feed processing, redirects were followed without validating the redirect scheme or destination. The original request headers were reused across redirect hops, meaning authentication headers or API credentials configured for a feed could be forwarded to a different host. Redirects could also target internal network resources, resulting in SSRF. The fix adds redirect validation, blocks internal destinations for cross-host redirects, strips configured feed credentials before following redirects to another host, and pins validated DNS results to prevent re-resolution after validation.

The TAXII discovery endpoint had a related incomplete SSRF defense. It used gethostbyname() and compared the result against only a few literal addresses. This missed cases including IPv6 loopback (::1), numeric host encodings such as 0x7f000001, and potentially multiple DNS records. The fix moves TAXII discovery to the shared URL egress validator.

Together, these commits harden MISP's outbound URL handling against alternate-address representations, DNS-related bypasses, unsafe redirects, internal-host access, and cross-host credential forwarding.

Version affected: ≤2.5.45

Affected versions of MISP expose organisation metadata through the dashboard organisation picker without applying the same visibility restrictions enforced by the normal organisation index and per-organisation view.

The affected endpoint returned fields including:

- organisation ID;

- UUID;

- name.

When Security.hideorganisationindexfromusers was enabled, normal organisation enumeration was restricted, but the dashboard picker still queried all organisations. This allowed authenticated users to discover organisations that should have remained hidden from them.

The fix calls Organisation::createConditions($this->Auth->user()) and appends the resulting ACL conditions to the picker query. Ordinary users are thereby limited to organisations associated with events or proposals they can already see, plus their own organisation, while users with the appropriate sharing-group privilege retain broader visibility.

Version affected: ≤2.5.45

Affected versions of MISP inconsistently enforced email-address visibility in DashboardsController::listTemplates().

The query always fetched User.email, while redaction happened only inside the non-REST rendering branch. As a result, the same authenticated user who saw redacted data in the normal HTML interface could request the REST/JSON representation and receive template owners’ email addresses without the intended privilege check.

The fix moves the decision to a centralized User::canSeeEmails() authorization helper. Email addresses are now fetched only when the requester is a site administrator or the instance explicitly enables Security.discloseuseremails. The same helper is also reused by other dashboard widgets to keep email-disclosure policy consistent.

Version affected: ≤2.5.45

Affected versions of MISP do not enforce parent-event visibility when serving cryptographic keys through CryptographicKeysController::view().

The vulnerable handler queried CryptographicKey directly using the supplied key ID and selected sensitive fields such as:

type

keydata

fingerprint

but did not fetch or authorize the associated parent event first.

The upstream commit explicitly states that cryptographicKeys/view could return a protected event’s signing key to any authenticated user.

The fix adds parentid and parenttype to the lookup and then enforces authorization through the associated event using fetchSimpleEvent($user, parentid). If the parent is not an Event, access is limited to site administrators.

Version affected: ≤2.5.45

Affected versions of MISP validate the user-configurable homepage by checking only whether the supplied path begins with /. That check is insufficient because protocol-relative URLs such as //attacker.example also begin with / but resolve to an external origin in browsers.

The vulnerable homepage value can be stored as a user setting and later used by the post-login routing logic. The commit explicitly identifies //attacker.example as a payload that passed validation and was emitted to the Location header after login.

The fix introduces a shared InternalRedirectValidator that rejects URLs containing a host, scheme, userinfo, unsafe leading // or /\, malformed URLs, and control characters. It also revalidates homepage settings on read so legacy or internally written unsafe values cannot bypass the new storage-time validation.

Version affected: ≤2.5.45

Affected versions of MISP allow any authenticated user to access TemplatesController::uploadFile() because the ACL entry for templates/uploadFile used the wildcard . This bypasses the intended role restrictions applied to neighboring template-management operations.

The upload handler accepts arbitrary content with only minimal checks and writes it into app/tmp/files/. A low-privileged or read-only user can therefore repeatedly upload files and consume server disk space without requiring permadd or permtemplate. The fix changes the ACL requirement from to permadd.

The commit also rules out stronger impacts: uploaded files receive random names, path traversal/predictable overwrite is not available, the temporary directory is outside the web root, and the files are not directly served over HTTP. Therefore, the issue should not be described as arbitrary file overwrite, stored XSS, or RCE.

Version affected: ≤2.5.45

Affected versions of MISP contain improper authorization checks in the freetext feed preview functionality. The preview performed correlation lookups against attributes from events without applying the requesting user's ACL, allowing restricted event correlations and associated event information to be exposed to users who could not otherwise access those events. The vulnerable queries were scoped only by attribute values and deletion status rather than MISP's event, organization, sharing-group, attribute, and object-level access controls.

The same preview functionality also returned cross-feed correlation information without properly restricting the feed list to feeds visible to the caller. This exposed metadata for feeds that were not marked lookupvisible; one affected response additionally included the configured feed URL even though that value was not required by the feature.

The fixes apply the caller's ACL to attribute correlation searches, remove feed URLs from correlation results, restrict cross-feed results according to feed visibility, and correct host-organization ID comparison so the authorization rules are applied consistently.

Version affected: ≤2.5.45

A vulnerability in MISP's event template handling allowed an authenticated user with permission to create or modify event templates to bypass validation of the template definition field.

The EventTemplate::beforeValidate() method only performed semantic validation when the supplied definition was already represented as an array. If a caller instead supplied a pre-encoded string, including malformed JSON or JSON representing an unexpected data type, the value bypassed validateDefinition() and only needed to satisfy the generic notBlank validation rule. As a result, an invalid event template definition could be stored persistently in the database.

When event templates were subsequently retrieved, EventTemplate::afterFind() attempted to decode the stored definition using JsonTool::decode() without handling decoding failures. A definition containing invalid JSON could therefore trigger an exception during retrieval. Because the event template index is available to all authenticated users, a single malicious or malformed template could make the event template listing and other functionality relying on EventTemplate queries return HTTP 500 errors until the offending database row was manually repaired.

Valid JSON representing an unexpected type, rather than the expected JSON object, could similarly result in invalid data reaching downstream consumers.

The vulnerability can therefore be exploited by a user capable of saving event templates to persist malformed template data and cause a persistent denial of service against event-template functionality for other users.

The patch enforces that event template definitions must be supplied as structured objects before saving and always applies semantic validation. On retrieval, malformed JSON and definitions that do not decode to the expected structure are caught, logged, and replaced with an empty definition, preventing a malformed database entry from breaking all event template queries.

Poisoning doesn't seem reachable according to the lead developer.

MISP contains a session fixation vulnerability in the CustomAuth authentication (a custom configuration) flow. When a user was successfully authenticated through CustomAuth, MISP stored the authenticated user identity in the existing session without first rotating the session identifier.

As a result, if an attacker can cause a victim to use a session identifier known to the attacker before authentication, that same session identifier remains valid after the victim successfully authenticates. The attacker could subsequently reuse the fixed session identifier to access the victim's authenticated MISP session, potentially gaining the privileges associated with the victim's account.

The issue occurs because customAuthentication() wrote the authenticated user into the existing CakePHP session while the call to Session->renew() had previously been disabled. The patch restores session identifier rotation when a new authentication occurs or when the authenticated user changes, while avoiding unnecessary session renewal on every request.

A vulnerability in MISP's email-based one-time password (OTP) authentication flow allowed an attacker to perform an unrestricted number of OTP verification attempts.

The emailotp() endpoint did not apply brute-force protection when validating submitted OTP values. An attacker who had reached the OTP verification stage, for example after successfully providing a user's primary authentication credentials, could repeatedly submit candidate OTP values while the same OTP remained valid. This significantly increased the feasibility of guessing the OTP and bypassing the additional authentication factor, potentially resulting in unauthorized access to the affected user's account.

The issue was exacerbated by the fact that the OTP is associated with the user rather than with an individual pending login session, allowing multiple concurrent sessions to attempt guesses against the same valid OTP.

The patch integrates the existing MISP brute-force protection mechanism into the email OTP flow. Failed OTP attempts are now counted against the user, further attempts are rejected once the configured threshold is reached, and the active OTP is invalidated when the attempt budget is exhausted. Blocklisted users are also prevented from requesting the generation of a fresh OTP. In addition, OTP comparison now uses hashequals() and validates that the submitted value is a string.

A cross-site request forgery (CSRF) vulnerability existed in the cullEmptyEvents action of MISP. The endpoint performed a state-changing and irreversible operation while accepting HTTP GET requests.

Because bodyless GET requests are not subject to CakePHP's CSRF validation, an attacker could cause an authenticated MISP user with sufficient privileges to invoke the endpoint simply by causing their browser to load a crafted URL, for example through an embedded image or other automatically requested resource.

Successful exploitation triggers the deletion of published empty events. The deletion is particularly significant because the operation uses skipBlocklist, meaning the removed events do not leave blocklist entries that could prevent or track their subsequent synchronization. This can result in unintended and potentially irreversible deletion of MISP event records without explicit user interaction.

The vulnerability was addressed by restricting cullEmptyEvents to HTTP POST requests, ensuring that CakePHP's normal CSRF protections are applied to the operation.

A persistent unsafe URL injection vulnerability exists in the MISP dashboard ButtonWidget configuration. Dashboard widget URLs were validated only when the widget was rendered and were not validated when the configuration was saved. As a result, an authenticated user able to modify dashboard widget settings could persist arbitrary URL values, including URLs using the javascript: scheme, through either of the dashboard settings persistence paths.

A malicious javascript: URL stored in a dashboard button could potentially result in client-side script execution in the MISP security context if the value reached a rendering or navigation path without the existing runtime validation. Such execution could allow an attacker to perform actions with the privileges of the affected user or access information available to their MISP session.

The practical exploitability of this issue is reduced by the fact that MISP already applied URL validation at render time, which neutralized known malicious values before they were presented to the user. The vulnerability therefore represents a persistence-layer validation gap and a defense-in-depth weakness rather than evidence of a direct bypass of the existing rendering protection.

The patch introduces a canonical url schema type and validates dashboard widget configuration before it is persisted through either settings save mechanism. ButtonWidget URLs must now be strings resolving to an absolute path on the current MISP instance or a full URL with the same origin. Values using javascript:, external origins, malformed URL forms, and non-string values are rejected at save time.

MISP contains a reflected Cross-Site Scripting (XSS) vulnerability in the event attribute filtering query builder. The taggedAttributes and galaxyAttachedAttributes URL parameters were inserted into the query-builder rules without HTML escaping before being serialized as JSON and embedded inside a <script> element.

Because JsonTool::encode() uses JSONUNESCAPEDSLASHES, an attacker-controlled value containing a closing </script> sequence could terminate the surrounding script element and inject arbitrary HTML or JavaScript. For example, a specially crafted viewEventAttributes URL could contain malicious content in one of the affected filter parameters.

An attacker could exploit the vulnerability by convincing an authenticated MISP user to follow a crafted URL. Successful exploitation would execute attacker-controlled JavaScript in the security context of the MISP instance and with the privileges of the victim's authenticated browser session. This could allow access to information available to the victim, modification of data through authenticated requests, or other actions permitted by the victim's MISP permissions.

The vulnerability is addressed by applying HTML escaping with h() to both scalar and array values before they are inserted into the DOM.

MISP contains an authorization flaw in the OnDemand correlation engine where correlations were calculated solely from matching attribute values without applying the distribution, sharing group, organization, or other access-control restrictions associated with the correlated attributes and events. As a result, an authenticated user could receive correlation results referring to attributes or events that the user was not authorized to access.

The vulnerable correlation collection path did not take the requesting user into account. The patch changes the correlation collector to accept the current user and filters the resulting attribute identifiers through MISP's existing fetchAttributesSimple() authorization logic, which evaluates event-, attribute-, object-, distribution-, and sharing-group-level restrictions against the live data.

The issue also affected paths relying on previously stored correlation data. Because the OnDemand engine does not maintain the stored correlation table, its denormalized access-control information could be stale. The patch therefore validates correlated attribute identifiers against the current ACLs before returning them and additionally applies normal event visibility conditions when retrieving related events.

An authenticated low-privileged user could exploit this issue by querying or creating attributes that correlate with restricted MISP content, potentially learning information about otherwise inaccessible events or attributes.

MISP contains an improper TLS certificate validation vulnerability in CurlClient. The CurlClient::$verifyPeer property was not explicitly initialized and therefore defaulted to null. When passed to cURL, this value effectively disabled TLS peer verification unless the calling code explicitly enabled it.

As a result, HTTPS connections made through affected CurlClient instances could accept certificates that were not issued by a trusted certificate authority. An attacker capable of intercepting or manipulating network traffic between a MISP instance and a remote HTTPS service could impersonate the remote endpoint and perform a man-in-the-middle attack.

Successful exploitation could allow an attacker to observe sensitive information transmitted by MISP, including authentication material or exchanged threat intelligence, and to modify responses returned to the MISP instance. The impact depends on the functionality using CurlClient and the data exchanged with the remote service.

The patch enables TLS peer verification by default while preserving explicit support for configured self-signed certificates. It also corrects the self-signed certificate handling in SyncTool so that peer verification is disabled only when no pinned CA certificate is configured.

MISP contains an authentication bypass vulnerability in its LDAP and LinOTP authentication components due to insufficient validation of user-supplied credentials.

The custom LdapAuthenticate and LinOTPAuthenticate components replace CakePHP's FormAuthenticate implementation but did not replicate its credential validation checks. As a result, empty or non-string values could reach the underlying authentication mechanisms.

In the LDAP authentication path, an attacker able to identify a valid directory user's email address could submit an empty password. The empty credential could be passed to ldapbind(), where an LDAP server accepting unauthenticated binds may return a successful result for a valid distinguished name combined with an empty password. MISP could consequently treat the attacker as the corresponding authenticated directory user without verification of the user's password.

The issue also affected the LinOTP authentication component. Invalid credential types were not rejected before being processed, and when mixed authentication was enabled, an empty password could be checked against a locally stored MISP password hash. LDAP-provisioned MISP accounts could additionally be created with an empty local password because account creation skipped normal validation, resulting in a hash corresponding to an empty password. This could permit authentication through the local fallback mechanism when such an account was no longer resolved through LDAP.

Successful exploitation could allow a remote unauthenticated attacker to impersonate an existing MISP user. If the targeted account has administrative or other privileged permissions, the attacker could gain corresponding access to sensitive threat-intelligence data, modify or delete information, alter configuration, or perform other privileged operations.

The patch resolves the vulnerability by requiring authentication identifiers and passwords to be valid strings, rejecting empty passwords where they are not explicitly permitted, and assigning a randomly generated local password to LDAP-provisioned accounts instead of storing a hash derived from an empty password.

MISP allowed an authenticated site administrator to set the Kafkardkafkaconfig setting to an arbitrary filesystem path. MISP subsequently parsed the referenced INI file and passed its options to rdkafka. A crafted attacker-controlled configuration file could use rdkafka options such as plugin.library.paths to load an external library, resulting in arbitrary code execution with the privileges of the MISP process. An attacker could leverage a MISP-writable location, such as an uploaded file or administrative image, to host the malicious configuration file.

The issue is fixed by restricting the setting to absolute .ini files located only in approved configuration directories outside the webroot and MISP upload targets.

MISP allowed a site administrator to configure an arbitrary filesystem path for the NDJSON error log used by JsonLogTool. Because log entries can include attacker-controlled content, an authenticated attacker with site administrator privileges could direct log output to a PHP file in a web-accessible directory and inject PHP code through logged data. Accessing the resulting file could lead to remote code execution with the privileges of the web server process.

The fix restricts log destinations to existing directories beneath APP/tmp/logs or /var/log, requires absolute paths, rejects stream wrappers and traversal-related input, and limits filenames to .log or .ndjson extensions while disallowing executable extension segments.

The Azure Active Directory (AAD) authentication implementation contained multiple weaknesses in its OAuth 2.0 authorization flow that could allow attackers to bypass important security guarantees provided by the protocol.

The application used the PHP session identifier (sessionid()) as the OAuth state parameter. Because session identifiers are long-lived authentication credentials, exposing them in OAuth redirect URLs could leak valid session tokens through browser history, HTTP Referer headers, reverse proxies, access logs, or third-party infrastructure involved in the authentication flow. If obtained by an attacker, the leaked session identifier could potentially be used for session hijacking.

Additionally, the implementation did not regenerate the session identifier after successful authentication, leaving authenticated sessions susceptible to session fixation attacks where an attacker forces a victim to use a known session identifier before login and later reuses that identifier after authentication.

The OAuth state value was also not implemented as a dedicated, single-use nonce. This weakened CSRF protections and increased the risk of replay attacks against the OAuth callback process.

The authentication flow further failed to enforce HTTPS for the configured OAuth redirect URI. If a non-HTTPS redirect URI was used, OAuth authorization codes and access tokens could traverse the network in plaintext, exposing sensitive credentials to network attackers.

Finally, OAuth error responses containing attacker-controlled GET parameters were logged verbatim. An attacker could inject control characters or crafted log content, leading to log forging, log injection, or corruption of audit records.

The fix introduces:

A dedicated cryptographically random OAuth state value.

Single-use state validation and invalidation.

Constant-time state comparison using hashequals().

Session identifier rotation after successful authentication.

Enforcement of HTTPS-only redirect URIs.

Sanitized and length-limited logging of OAuth error parameters.

AAD Authentication Plugin (OAuth 2.0 / Azure Active Directory integration)

MISP core contained multiple broken access-control flaws where authorization checks were performed against the wrong entity, or where ownership/editability checks were missing on write paths. In affected subsystems, a lower-privileged authenticated user with the relevant feature permission could cause the application to authorize one object but mutate another, or could modify objects that were merely visible rather than editable by the user’s organization.

The affected paths included:

Event Reports tag removal: the route-authorized report could differ from the report ID used for tag detachment, enabling cross-organization tag removal from another event report

Collection Elements bulk deletion: bulk deletion authorized against a collection whose ID matched the collection-element row ID, rather than the element’s actual parent collection, enabling deletion of elements from collections the user did not own. Analyst Data capture/update: nested analyst data updates could overwrite an existing record without applying the normal canEditAnalystData ownership check, enabling cross-organization overwrite of analyst data records. Template Elements editing: editing authorized against a template whose ID matched the template-element ID, rather than the element’s actual parent template, enabling unauthorized edits to another organization’s template elements. Decaying Model editing and mappings: write paths loaded models using view-scope access but did not verify edit ownership, enabling users to edit or remap visible models owned by another organization.

Successful exploitation could allow an authenticated user with subsystem-specific permissions to perform unauthorized cross-organization modifications or deletions of MISP data, resulting in integrity loss, unauthorized tampering with shared intelligence, and disruption of analyst workflows.

MISP Core contained broken access-control checks in the bulk deletion flows for Event Reports and Sharing Groups. The affected deleteSelection handlers authorized deletion using broad role-level permissions instead of validating authorization for each selected object.

For Event Reports, EventReportsController::deleteSelection relied on the global permadd capability rather than a per-report ownership/authorization check. As a result, a contributor-level user could submit report IDs or UUIDs for reports belonging to other organisations and hard-delete them instance-wide. The fix changed the callback to call EventReport::fetchIfAuthorized($user, $itemId, 'delete') for each selected report before deletion.

For Sharing Groups, SharingGroupsController::deleteSelection relied on the global permsharinggroup capability rather than verifying ownership of each selected sharing group. This allowed a sharing-group-capable user to hard-delete sharing groups owned by other organisations, bypassing the per-object ownership gate used by the single-object delete action. The fix changed the callback to call SharingGroup::checkIfOwner($user, $itemId) for each selected sharing group.

An authenticated attacker with the relevant broad role permission could abuse the affected bulk deletion endpoints to delete objects outside their organisation’s authorization scope, causing loss of event-report content or sharing-group configuration across the instance.

A vulnerability in the MISP dashboard widgets allowed an authenticated user to manipulate the fields option and influence which fields were returned by the New Users and New Organisations widgets. In some cases, requesting a field set that became empty after validation or redaction could cause the underlying query to fall back to returning unintended model fields.

For the New Users widget, this could allow a non-site-admin user to obtain user e-mail addresses even when user e-mail disclosure was disabled by configuration. For the New Organisations widget, crafted field selection could similarly result in unintended organisation fields being included in the dashboard response.

The issue was caused by applying field filtering and redaction in a way that could leave the selected field list empty. The patch ensures that the allowed field list is built safely, that restricted fields such as user e-mail addresses are removed before user-supplied field selection is processed, and that an empty field selection falls back only to the permitted default fields.

Impact: An authenticated low-privileged user with access to the affected dashboard widgets may be able to disclose restricted user or organisation metadata, including user e-mail addresses depending on configuration.

A security issue was fixed in the correlations over-correlation endpoint where the order query parameter was accepted from user-controlled named request parameters. This allowed an authenticated user to override the server-defined ordering of over-correlating values. Depending on how the value was processed by the underlying data access layer, this could allow manipulation of database query ordering and potentially expose the application to unsafe query construction.

The patch removes order from the set of request-controlled parameters and instead sets the ordering server-side to occurrence desc after processing allowed user parameters.

Affected component: app/Controller/CorrelationsController.php, overCorrelations()

Security impact: An authenticated attacker could influence the ordering clause used by the over-correlations query. The direct impact appears limited to query manipulation unless further evidence confirms SQL injection or unauthorized data exposure through the manipulated ordering expression.

A logic error in the MISP CRUD component delete handler allowed validation failures to be bypassed when requests used the HTTP DELETE method. Due to missing parentheses in the delete condition, the expression was evaluated as ($validationError === null && POST) || DELETE, meaning a DELETE request could proceed even when the delete validation callback had rejected the operation. An authenticated attacker with access to an affected delete endpoint could abuse this flaw to delete records that should have been protected by application-level validation or authorization checks.

An open redirect vulnerability existed in MISP UsersController::routeafterlogin() because the value stored in the preloginrequestedurl session key was used as the post-login redirect destination without sufficiently enforcing that it was a local application path.

An unauthenticated remote attacker could craft a link that causes a victim to visit a trusted MISP instance and, after successful authentication, be redirected to an attacker-controlled external URL. This could be abused to increase the credibility of phishing attacks, redirect users to counterfeit login pages, or deliver attacker-controlled content from an untrusted domain. CWE-601 describes this weakness as accepting user-controlled input that specifies an external link and using it in a redirect, with phishing as a common consequence.

The patch mitigates the issue by decoding and parsing the URL, rejecting URLs with a scheme, host, user component, missing or non-local path, and protocol-relative forms such as //example.com and /\example.com.

A URL validation flaw in the MISP dashboard button widget allowed a crafted relative-looking URL to be accepted as a local path while being interpreted by browsers as an external URL. The validation rejected URLs containing an explicit scheme, host, or user component, but did not reject paths beginning with a slash followed by a backslash, such as /\example.com. Some browsers normalize backslashes in URLs as forward slashes, which can turn this into a scheme-relative external navigation target. In addition, the generated href concatenated the reconstructed URL with the original URL, increasing the possibility of unsafe or malformed link generation.

An attacker able to configure or influence a dashboard button URL could craft a button that appears to point inside the application but redirects users to an attacker-controlled site when clicked. This could be used for phishing, credential theft, or social engineering. The patch fixes the issue by rejecting empty paths and paths starting with /\, and by emitting only the reconstructed validated URL in the anchor href.