CVE-2026-55552 json
Yamcs: Unauthenticated Directory Traversal
published 2026-08-28 2 mo ago modified 2026-09-08 2 mo ago also GHSA-9jg3-g3wh-w9pj , EUVD-2026-67842
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.7%
- EPSS 1.7% chance of exploitation in 30 days, percentile 77%
- public exploits
- 0
- none known, plus a Nuclei check
Summary
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.
Patch / fix
- maven org.yamcs:yamcs-core 5.12.0
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
1.72% chance of exploitation in the next 30 days, higher than 77% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- Nuclei template Yamcs <=5.11.12 - Arbitrary File Read nuclei detection template
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
| GitHub | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| maven | org.yamcs:yamcs-core | <5.12.0 |
5.12.0 |
Affected products
- yamcs yamcs
Classification
- Weakness
-
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory
References
-
github.com
/yamcs/yamcs/commit/c7dfd24e469ae1086c23e0fe04401cb1ce4260d4
web
-
github.com
/yamcs/yamcs/commit/f4bc588880c166849e983aa8f65b9c8107d06091
web
-
github.com
/yamcs/yamcs/security/advisories/GHSA-9jg3-g3wh-w9pj
web
-
github.com
/yamcs/yamcs/releases/tag/yamcs-5.11.13
web
-
github.com
/yamcs/yamcs/releases/tag/yamcs-5.12.0
web
-
github.com
/yamcs/yamcs
package
Sources
- CVE List CVE-2026-55552
- GitHub Advisory GHSA-9jg3-g3wh-w9pj
- NVD CVE-2026-55552
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