CVE-2026-55552
HighYamcs has Unauthenticated Directory Traversal
Published Aug 28, 2026 · Updated Sep 10, 2026 · Also known as GHSA-9jg3-g3wh-w9pj
Key Facts
Patch in the next maintenance window- CVE-2026-55552 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting org.yamcs:yamcs-core (maven), yamcs.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 1.7% probability of exploitation in the next 30 days.
- Fixed versions are available, including org.yamcs:yamcs-core 5.11.13, org.yamcs:yamcs-core 5.12.0.
- Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS (30-day exploit likelihood)
1.7%
Higher than 77.1% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
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Description
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
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| org.yamcs:yamcs-coremaven | See advisory | 5.12.0 |
| yamcs | >= < 5.12.0 | n/a |
Patched Releases
org.yamcs:yamcs-core
5.11.13, 5.12.0
Timeline
Publicly disclosed
Aug 28, 2026
Last updated
Sep 10, 2026
Weakness Type
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
References
- advisoryGHSA advisory
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55552.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-55552
- articlehttps://github.com/yamcs/yamcs/commit/c7dfd24e469ae1086c23e0fe04401cb1ce4260d4
- articlehttps://github.com/yamcs/yamcs/commit/f4bc588880c166849e983aa8f65b9c8107d06091
FAQ
Common Questions.
Yamcs is a mission control framework.
Affected: org.yamcs:yamcs-core (maven); yamcs versions >= < 5.12.0. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including org.yamcs:yamcs-core 5.11.13, org.yamcs:yamcs-core 5.12.0.
Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
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