A path traversal flaw in the Projects Service download endpoint allows an authenticated user to supply a specially crafted path that bypasses validation and read arbitrary files from the server’s file system, including configuration files and credential material. This can expose sensitive data that can be used to further compromise the system or other services. The vulnerability can also be combined with another flaw (CVE‑2026‑11424) to reach cloud‑side endpoints, increasing the potential impact on multi‑tenant deployments.

The flaw affects Altium 365 and Altium Enterprise Server. Altium Enterprise Server is fixed in version 8.1.1. The issue has been remediated at the service level for Altium 365, but any deployment not yet updated may remain vulnerable.

With a CVSS score of 8.3 the vulnerability is classified as high severity. EPSS data is not available and the issue is not listed in the CISA KEV catalog, indicating no known widespread exploitation yet. Because the flaw requires authentication, the attack vector is "authenticated user", and the threat is limited to compromised credentials—though exposed configuration could enable cross‑tenant compromise in multi‑tenant Altium 365 setups.