CVE-2026-55552: Yamcs

High severity, CVSS 7.5. EPSS: 1.7% chance of exploitation in the next 30 days.

Yamcs is a mission control framework. Prior to 5.11.13, Yamcs StaticFileHandler.locateFile resolves an unauthenticated request path without using Path.normalize and Path.toAbsolutePath to confirm that the absolute path remains within the configured staticRoots. A path containing traversal segments can escape the intended web root and return an arbitrary readable host file. The flaw is in yamcs-core/src/main/java/org/yamcs/http/StaticFileHandler.java and can disclose sensitive operating-system and application data. This issue is fixed in version 5.11.13, and the 5.12 line is fixed from version 5.12.0.

Affected products

• Yamcs Yamcs: before 5.12.0 (fixed in 5.12.0)

Published 2026-08-28. Last modified 2026-09-08.