Improper authorization in yamcs
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-285.
Summary
Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, Yamcs omits SystemPrivilege.ControlAccess checks from IamApi.listRoles, IamApi.getRole, and IamApi.listPrivileges in yamcs-core/src/main/java/org/yamcs/http/api/IamApi.java. Any authenticated account can call GET /api/roles, GET /api/roles/{name}, and GET /api/privileges to enumerate available system privileges and configured role mappings. The disclosure reveals security configuration that can support targeted privilege-escalation attempts. This issue is fixed in versions 5.12.8 and 5.13.2.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| yamcs | yamcs | before 5.12.8; 5.13.0 to before 5.13.2 | 5.12.8, 5.13.2 | Patch available | CNA |
| — | org.yamcs:yamcs-core (Maven) | 5.13.0 to before 5.13.2 | 5.13.2 | Patch available | GHSA-cvw4-55pp-3hfq |
| — | org.yamcs:yamcs-core (Maven) | before 5.12.8 | 5.12.8 | Patch available | GHSA-cvw4-55pp-3hfq |
- yamcs Vendoryamcs Affected before 5.12.8; 5.13.0 to before 5.13.2 Fixed in 5.12.8, 5.13.2 Patch available CNA
- org.yamcs:yamcs-core (Maven) Vendor— Affected 5.13.0 to before 5.13.2 Fixed in 5.13.2 Patch available GHSA-cvw4-55pp-3hfq
- org.yamcs:yamcs-core (Maven) Vendor— Affected before 5.12.8 Fixed in 5.12.8 Patch available GHSA-cvw4-55pp-3hfq
Remediation
- Fix · CNA yamcs (yamcs) Fixed in 5.12.8, 5.13.2
- Fix · GHSA-cvw4-55pp-3hfq org.yamcs:yamcs-core (Maven) Fixed in 5.13.2 Advisory →
- Fix · GHSA-cvw4-55pp-3hfq org.yamcs:yamcs-core (Maven) Fixed in 5.12.8 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-55547
- 2026-10-03 Alias added: GHSA-cvw4-55pp-3hfq
References
Other 6
- https://github.com/yamcs/yamcs/security/advisories/GHSA-cvw4-55pp-3hfq
- https://github.com/yamcs/yamcs/commit/c2aec1c242e656e48b52c7f87deea88183bb592d
- https://github.com/yamcs/yamcs/commit/dcaec5f0b2f4231b8e313e94d79a937169c9e0ba
- https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.8
- https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.2
- https://github.com/yamcs/yamcs
More yamcs vulnerabilities
- TI-2026-40103 Yamcs: Remote Code Execution via instance-template argument YAML injection (createInstance) CVSS 3.1CRITICAL 9.8
- TI-2026-34240 Yamcs: Remote Code Execution via Mission Database algorithm override CVSS 3.1CRITICAL 9.8
- TI-2026-32507 Yamcs: No Rate Limiting on Authentication Endpoint CVSS 3.1CRITICAL 9.8
- TI-2026-40106 Yamcs: Authenticated remote code execution via unescaped StreamSQL `LIKE` pattern compiled by Janino (`LikeExpression`) CVSS 3.1CRITICAL 9.9
- TI-2026-40057 Yamcs: Authenticated RCE via StreamSQL aggregate-compiler column-name injection in Yamcs `executeSql` CVSS 3.1CRITICAL 9.1
- TI-2026-34277 Yamcs: Authenticated Remote Code Execution (RCE) via Jython Algorithm Code Injection CVSS 3.1CRITICAL 9.1
Sources
- CVE-2026-55547 · CVE Program
- CVE-2026-55547 · NVD
- FIRST EPSS
- GHSA-cvw4-55pp-3hfq · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences