CVE-2026-11431: Altium 365

High severity, CVSS 8.3. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Altium Altium 365: affected versions not specified
• Altium Altium Enterprise Server: before 8.1.1 (fixed in 8.1.1)

Published 2026-06-05. Last modified 2026-07-23.