A path traversal vulnerability exists in the Projects Service download endpoint shared by Altium Enterprise Server and Altium 365. An authenticated user can supply a crafted path parameter that bypasses validation, allowing arbitrary files (including entire directories returned as archives) to be read from the server filesystem.
Because the readable files include service configuration and credential material, exploitation can be used to gather information enabling further compromise. The issue can be combined with CVE-2026-11424 to reach the cloud-side endpoint. On multi-tenant Altium 365 deployments, the readable configuration could have exposed credentials shared across services. Altium Enterprise Server is fixed in 8.1.1; the issue has been remediated in Altium 365 at the service level.
Two endpoints in the Vault Service ScriptsController, shared by Altium Enterprise Server and Altium 365, accept file uploads where a user-supplied filename component is used to construct the destination path without validation, allowing arbitrary files to be written to any location writable by the service account. Because the file write operation completes before authentication is validated, the vulnerability can be exploited without any credentials, session, or prior knowledge of the system.
An unauthenticated network attacker can use this primitive to place executable content in directories where it is later executed by the service, resulting in remote code execution under the Vault Service account. Altium Enterprise Server is fixed in 8.1.1; the issue has been remediated in Altium 365 (commercial and government cloud) at the service level.
A server-side request forgery (SSRF) vulnerability exists in a GraphQL service component shared by Altium Enterprise Server and Altium 365. An authenticated user can submit a request whose input is treated as a URL by the server and used to issue an outbound HTTP GET request without URL validation or destination filtering. The response body is then returned to the user.
This allows an authenticated attacker to reach internal services and metadata endpoints that would not otherwise be accessible from the public network, and to retrieve their contents. The impact is information disclosure and internal infrastructure reconnaissance; the request primitive is limited to HTTP GET with no custom headers. Altium Enterprise Server is fixed in 8.1.1; the issue has been remediated in Altium 365 at the service level.
Altium 365 workspace endpoints were configured with an overly permissive Cross-Origin Resource Sharing (CORS) policy that allowed credentialed cross-origin requests from other Altium-controlled subdomains, including forum.live.altium.com. As a result, JavaScript executing on those origins could access authenticated workspace APIs in the context of a logged-in user. When chained with vulnerabilities in those external applications, this misconfiguration enables unauthorized access to workspace data, administrative actions, and bypass of IP allowlisting controls, including in GovCloud environments.
A stored cross-site scripting (XSS) vulnerability exists in the Altium Forum due to missing server-side input sanitization in forum post content. An authenticated attacker can inject arbitrary JavaScript into forum posts, which is stored and executed when other users view the affected post. Successful exploitation allows the attacker’s payload to execute in the context of the victim’s authenticated Altium 365 session, enabling unauthorized access to workspace data, including design files and workspace settings. Exploitation requires user interaction to view a malicious forum post.
A stored cross-site scripting (XSS) vulnerability exists in the user profile text fields of Altium 365. Insufficient server-side input sanitization allows authenticated users to inject arbitrary HTML and JavaScript payloads using whitespace-based attribute parsing bypass techniques. The injected payload is persisted and executed when other users view the affected profile page, potentially allowing session token theft, phishing attacks, or malicious redirects. Exploitation requires an authenticated account and user interaction to view the crafted profile.