HTTP/2 Rapid reset attack The HTTP/2 protocol allows clients to indicate to the server that a previous stream should be canceled by sending a RSTSTREAM frame. The protocol does not require the client and server to coordinate the cancellation in any way, the client may do it unilaterally. The client may also assume that the cancellation will take effect immediately when the server receives the RSTSTREAM frame, before any other data from that TCP connection is processed.
Abuse of this feature is called a Rapid Reset attack because it relies on the ability for an endpoint to send a RSTSTREAM frame immediately after sending a request frame, which makes the other endpoint start working and then rapidly resets the request. The request is canceled, but leaves the HTTP/2 connection open.
The HTTP/2 Rapid Reset attack built on this capability is simple: The client opens a large number of streams at once as in the standard HTTP/2 attack, but rather than waiting for a response to each request stream from the server or proxy, the client cancels each request immediately.
The ability to reset streams immediately allows each connection to have an indefinite number of requests in flight. By explicitly canceling the requests, the attacker never exceeds the limit on the number of concurrent open streams. The number of in-flight requests is no longer dependent on the round-trip time (RTT), but only on the available network bandwidth.
In a typical HTTP/2 server implementation, the server will still have to do significant amounts of work for canceled requests, such as allocating new stream data structures, parsing the query and doing header decompression, and mapping the URL to a resource. For reverse proxy implementations, the request may be proxied to the backend server before the RSTSTREAM frame is processed. The client on the other hand paid almost no costs for sending the requests. This creates an exploitable cost asymmetry between the server and the client.
Multiple software artifacts implementing HTTP/2 are affected. This advisory was originally ingested from the swift-nio-http2 repo advisory and their original conent follows.
swift-nio-http2 specific advisory swift-nio-http2 is vulnerable to a denial-of-service vulnerability in which a malicious client can create and then reset a large number of HTTP/2 streams in a short period of time. This causes swift-nio-http2 to commit to a large amount of expensive work which it then throws away, including creating entirely new Channels to serve the traffic. This can easily overwhelm an EventLoop and prevent it from making forward progress.
swift-nio-http2 1.28 contains a remediation for this issue that applies reset counter using a sliding window. This constrains the number of stream resets that may occur in a given window of time. Clients violating this limit will have their connections torn down. This allows clients to continue to cancel streams for legitimate reasons, while constraining malicious actors.
Cleartext Transmission of Sensitive Information vulnerability in Apache APISIX.
tencent-cloud-cls log export uses plaintext HTTP This issue affects Apache APISIX: from 2.99.0 through 3.15.0.
Users are recommended to upgrade to version 3.16.0, which fixes the issue.
Cleartext Transmission of Sensitive Information vulnerability in Apache APISIX.
This can occur due to sslverify in openid-connect plugin configuration being set to false by default. This issue affects Apache APISIX: from 0.7 through 3.15.0.
Users are recommended to upgrade to version 3.16.0, which fixes the issue.
Header injection vulnerability in Apache APISIX.
The attacker can take advantage of certain configuration in forward-auth plugin to inject malicious headers. This issue affects Apache APISIX: from 2.12.0 through 3.15.0.
Users are recommended to upgrade to version 3.16.0, which fixes the issue.
Sensitive data exposure via logging in basic-auth leads to plaintext usernames and passwords written to error logs and forwarded to log sinks when log level is INFO/DEBUG. This creates a high risk of credential compromise through log access. It has been fixed in the following commit: https://github.com/apache/apisix/pull/12629 Users are recommended to upgrade to version 3.14, which fixes this issue.
Cross-Site request forgery (CSRF) vulnerability in feishu-auth and dingtalk-auth plugins in Apache APISIX.
An attacker who can get a user to click a crafted link may cause that user's browser session on a protected route to be established under the attacker's identity instead of their own. Any work the user then performs in that session, including uploads, form submissions, and account bindings, lands in the attacker's account. This issue affects Apache APISIX: from 3.17.0 through 3.18.0.
Users are recommended to upgrade to version 3.19.0, which fixes the issue.
Improper Authentication vulnerability in Apache APISIX.
On a route using openid-connect plugin with remote introspection against an authorization server that serves multiple issuers, a token that introspects as active for one issuer may get accepted on a route restricted to another. This issue affects Apache APISIX: from 3.12.0 through 3.18.0.
Users are recommended to upgrade to version 3.19.0, which fixes the issue.
Use of Non-Canonical URL paths for authorization decisions vulnerability in Apache APISIX.
In some configurations where a permissive route overlaps a protected one, a crafted encoded path can reach an upstream endpoint that the matched route's policies were never meant to cover. A request that should have been rejected is served instead, giving unauthenticated access to a protected upstream endpoint. This issue affects Apache APISIX: from 2.14.1 through 3.18.0.
Users are recommended to upgrade to version 3.19.0, which fixes the issue.
Allocation of resources without limits or throttling vulnerability in batch-requests plugin in Apache APISIX.
An unauthenticated caller can drive a gateway worker into OOM via a route where the batch-requests plugin is used and the batch endpoint is publicly exposed. This issue affects Apache APISIX: from 1.3.0 through 3.18.0.
Users are recommended to upgrade to version 3.19.0, which fixes the issue.
Improper verification of cryptographic signature vulnerability in Apache APISIX.
Any unauthenticated attacker could impersonate any user on every route protected by the saml-auth plugin under default configuration. This issue affects Apache APISIX: from 3.17.0 through 3.18.0.
Users are recommended to upgrade to version 3.19.0, which fixes the issue.
Exposure of data element to wrong session vulnerability in Apache APISIX.
This issue affects Apache APISIX: from 2.3.0 before 3.7.0.
Under a supported authz-keycloak configuration, a request's authorization scope could persist into later requests on the same route, leading to unintended authorization expansion and inconsistent access-control decisions.
Users are recommended to upgrade to version 3.7.0 or higher, which fixes the issue.
Insertion of sensitive information into log file vulnerability in Apache APISIX.
This vulnerability can cause the unmasked header value to be written to the log sink under a certain response structure.
This issue affects Apache APISIX: 3.17.0.
Users are recommended to upgrade to version 3.18.0, which fixes the issue.
Severity: CVSS 4.0: 5.1 (medium) CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N
Affected versions:
- Apache APISIX 3.12.0 through 3.18.0
Description:
Improper Authentication vulnerability in Apache APISIX.
On a route using openid-connect plugin with remote introspection against an authorization server that serves multiple issuers, a token that introspects as active for one issuer may get accepted on a route restricted to another. This issue affects Apache APISIX: from 3.12.0 through 3.18.0.
Users are recommended to upgrade to version 3.19.0, which fixes the issue.
Credit:
sec-reex (reporter) shreemaan-abhishek (coordinator) shreemaan-abhishek (remediation developer)
References:
https://apisix.apache.org https://www.cve.org/CVERecord?id=CVE-2026-94276
Severity: CVSS 4.0: 6.3 (medium) CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Affected versions:
- Apache APISIX 2.14.1 through 3.18.0
Description:
Use of Non-Canonical URL paths for authorization decisions vulnerability in Apache APISIX.
In some configurations where a permissive route overlaps a protected one, a crafted encoded path can reach an upstream endpoint that the matched route's policies were never meant to cover. A request that should have been rejected is served instead, giving unauthenticated access to a protected upstream endpoint. This issue affects Apache APISIX: from 2.14.1 through 3.18.0.
Users are recommended to upgrade to version 3.19.0, which fixes the issue.
Credit:
Ziyue (reporter) shreemaan-abhishek (coordinator) shreemaan-abhishek (remediation developer)
References:
https://apisix.apache.org https://www.cve.org/CVERecord?id=CVE-2026-94269
Severity: CVSS 4.0: 8.2 (high) CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected versions:
- Apache APISIX 1.3.0 through 3.18.0
Description:
Allocation of resources without limits or throttling vulnerability in batch-requests plugin in Apache APISIX.
An unauthenticated caller can drive a gateway worker into OOM via a route where the batch-requests plugin is used and the batch endpoint is publicly exposed. This issue affects Apache APISIX: from 1.3.0 through 3.18.0.
Users are recommended to upgrade to version 3.19.0, which fixes the issue.
Credit:
Ziyue (reporter) shreemaan-abhishek (remediation developer) shreemaan-abhishek (coordinator)
References:
https://apisix.apache.org https://www.cve.org/CVERecord?id=CVE-2026-94250
Severity: CVSS 4.0: 2.1 (low) CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Affected versions:
- Apache APISIX 3.17.0 through 3.18.0
Description:
Cross-Site request forgery (CSRF) vulnerability in feishu-auth and dingtalk-auth plugins in Apache APISIX.
An attacker who can get a user to click a crafted link may cause that user's browser session on a protected route to be established under the attacker's identity instead of their own. Any work the user then performs in that session, including uploads, form submissions, and account bindings, lands in the attacker's account. This issue affects Apache APISIX: from 3.17.0 through 3.18.0.
Users are recommended to upgrade to version 3.19.0, which fixes the issue.
Credit:
MopMonk-AI (reporter) shreemaan-abhishek (coordinator) shreemaan-abhishek (remediation developer)
References:
https://apisix.apache.org https://www.cve.org/CVERecord?id=CVE-2026-94220
Severity: CVSS 4.0: 6.4 (medium) CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
Affected versions:
- Apache APISIX 3.17.0 through 3.18.0
Description:
Improper verification of cryptographic signature vulnerability in Apache APISIX.
Any unauthenticated attacker could impersonate any user on every route protected by the saml-auth plugin under default configuration. This issue affects Apache APISIX: from 3.17.0 through 3.18.0.
Users are recommended to upgrade to version 3.19.0, which fixes the issue.
Credit:
LucasFutures (reporter) shreemaan-abhishek (coordinator) shreemaan-abhishek (remediation developer)
References:
https://apisix.apache.org https://www.cve.org/CVERecord?id=CVE-2026-94212
Severity: CVSS 4.0: 5.3 (medium) CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Affected versions:
- Apache APISIX 2.3.0 before 3.7.0
Description:
Exposure of data element to wrong session vulnerability in Apache APISIX.
This issue affects Apache APISIX: from 2.3.0 before 3.7.0.
Under a supported authz-keycloak configuration, a request's authorization scope could persist into later requests on the same route, leading to unintended authorization expansion and inconsistent access-control decisions.
Users are recommended to upgrade to version 3.7.0 or higher, which fixes the issue.
Credit:
Lok (reporter)
References:
https://apisix.apache.org https://www.cve.org/CVERecord?id=CVE-2026-82806
Severity: CVSS 4.0: 5.7 (medium) CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Affected versions:
- Apache APISIX 3.17.0
Description:
Insertion of sensitive information into log file vulnerability in Apache APISIX.
This vulnerability can cause the unmasked header value to be written to the log sink under a certain response structure.
This issue affects Apache APISIX: 3.17.0.
Users are recommended to upgrade to version 3.18.0, which fixes the issue.
Credit:
Jonas Schültke (reporter)
References:
https://apisix.apache.org https://www.cve.org/CVERecord?id=CVE-2026-78242
Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection') vulnerability in Apache APISIX.
A caller who holds valid credentials for one entry in the LDAP directory can authenticate through APISIX as a consumer mapped to a different entry, one the plugin's configured scope was meant to keep out of reach.
This issue affects Apache APISIX: from 2.11.0 through 3.17.0.
Users are recommended to upgrade to version 3.18.0, which fixes the issue.
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache APISIX.
An attacker could make other clients receive attacker-chosen or other users' responses on serverless-plugin routes.
This issue affects Apache APISIX: from 2.12.0 through 3.17.0.
Users are recommended to upgrade to version 3.18.0, which fixes the issue.
Inefficient Algorithmic Complexity vulnerability in Apache APISIX.
A single small request can pin a gateway worker at 100% CPU for an extended period in graphql-limit-count routes.
This issue affects Apache APISIX: 3.17.0.
Users are recommended to upgrade to version 3.18.0, which fixes the issue.
Reliance on Untrusted Inputs in a Security Decision vulnerability in Apache APISIX.
This vulnerability allows an attacker to escalate privilege or perform an authorization bypass by sending certain values that the attach-consumer-label plugin does not sanitise correctly.
This issue affects Apache APISIX: from 3.11.0 through 3.17.0.
Users are recommended to upgrade to version 3.18.0, which fixes the issue.
Severity:
Affected versions:
- Apache APISIX 2.12.0 through 3.17.0
Description:
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache APISIX.
An attacker could make other clients receive attacker-chosen or other users' responses on serverless-plugin routes.
This issue affects Apache APISIX: from 2.12.0 through 3.17.0.
Users are recommended to upgrade to version 3.18.0, which fixes the issue.
Credit:
Xclow3n (Rajat Raghav) (reporter)
References:
https://apisix.apache.org https://www.cve.org/CVERecord?id=CVE-2026-74848
Severity:
Affected versions:
- Apache APISIX 3.11.0 through 3.17.0
Description:
Reliance on Untrusted Inputs in a Security Decision vulnerability in Apache APISIX.
This vulnerability allows an attacker to escalate privilege or perform an authorization bypass by sending certain values that the attach-consumer-label plugin does not sanitise correctly.
This issue affects Apache APISIX: from 3.11.0 through 3.17.0.
Users are recommended to upgrade to version <pending>, which fixes the issue.
Credit:
tonghuaroot (reporter)
References:
https://apisix.apache.org https://www.cve.org/CVERecord?id=CVE-2026-63041
Cross-Site Request Forgery (CSRF) vulnerability in the cas-auth plugin under default configurations.
This defect allows a remote attacker that manages to send a victim to a webpage controlled by them can cause the victim's browser to become authenticated as a different identity.
Actions the victim takes upstream are then attributed to attackers identity.
This issue affects Apache APISIX: from 3.0.0 through 3.16.0.
Users are recommended to upgrade to version 3.17.0, which fixes the issue.
Improper Authentication vulnerability in Apache APISIX.
When the cas-auth plugin is used in a route, an attacker can possibly authenticate itself with credentials from a different source. This issue affects Apache APISIX: from 3.0.0 through 3.16.0.
Users are recommended to upgrade to version 3.17.0, which fixes the issue.
Authentication Bypass by Spoofing vulnerability in opa plugin.
An attacker could relay spoofed identity headers to upstream capitalising on non-default configuration in opa plugin.
This could allow the attacker to assume higher privileges on the upstream service. This issue affects Apache APISIX: from 3.5.0 through 3.16.0.
Users are recommended to upgrade to version 3.17.0, which fixes the issue.
Improper Validation of Integrity Check Value vulnerability in Apache APISIX.
The jwe-decrypt plugin under default configuration is vulnerable to authentication bypass. This issue affects Apache APISIX: from 3.8.0 through 3.16.0.
Users are recommended to upgrade to version 3.17.0, which fixes the issue.
URL Redirection to Untrusted Site ('Open Redirect') vulnerability in Apache APISIX.
The attacker could manipulate some client headers to perform an open-redirect, to potentially expose the session token.
This issue affects Apache APISIX: from 3.0.0 through 3.16.0.
Users are recommended to upgrade to version 3.17.0, which fixes the issue.