CVE-2026-55552

HIGH 7.5

Yamcs: Unauthenticated Directory Traversal

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-22
Vendor	yamcs
Product	yamcs
Published	Aug 28, 2026
Last Updated	Aug 28, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Affected Versions

yamcs / yamcs

< 5.12.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/yamcs/yamcs/security/advisories/GHSA-9jg3-g3wh-w9pj github.com: https://github.com/yamcs/yamcs/commit/c7dfd24e469ae1086c23e0fe04401cb1ce4260d4 github.com: https://github.com/yamcs/yamcs/commit/f4bc588880c166849e983aa8f65b9c8107d06091 github.com: https://github.com/yamcs/yamcs/releases/tag/yamcs-5.11.13 github.com: https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.0