Yamcs: Authenticated remote code execution via unescaped StreamSQL `LIKE` pattern compiled by Janino (`LikeExpression`)
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-94.
Summary
Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, Yamcs LikeExpression.fillCode_getValueReturn in yamcs-core/src/main/java/org/yamcs/yarch/streamsql/LikeExpression.java inserts an unescaped LIKE pattern into Java source compiled by Expression.getCompiledExpression through SimpleCompiler.cook instead of applying ValueExpression.escapeJavaString. The pattern can originate from POST /api/archive/{instance}:executeSql, POST /api/archive/{instance}:streamSql, POST /api/archive/{instance}/tables/{table}:readRows, GET /api/archive/{instance}/events, or activity searches, including paths available with ReadTables, ReadEvents, or ReadActivities. A quote in the pattern can inject Java that runs as the Yamcs server process. 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
- Total
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-c64q-hj4j-375f |
| — | org.yamcs:yamcs-core (Maven) | before 5.12.8 | 5.12.8 | Patch available | GHSA-c64q-hj4j-375f |
- 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-c64q-hj4j-375f
- org.yamcs:yamcs-core (Maven) Vendor— Affected before 5.12.8 Fixed in 5.12.8 Patch available GHSA-c64q-hj4j-375f
Remediation
- Fix · CNA yamcs (yamcs) Fixed in 5.12.8, 5.13.2
- Fix · GHSA-c64q-hj4j-375f org.yamcs:yamcs-core (Maven) Fixed in 5.13.2 Advisory →
- Fix · GHSA-c64q-hj4j-375f org.yamcs:yamcs-core (Maven) Fixed in 5.12.8 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-55565
- 2026-10-03 Alias added: GHSA-c64q-hj4j-375f
- 2026-10-16 EPSS moved to the 50th–90th percentile
References
Other 6
- https://github.com/yamcs/yamcs/security/advisories/GHSA-c64q-hj4j-375f
- https://github.com/yamcs/yamcs/commit/640e1598b7097b521692e89dd47a39b6cb1fc663
- https://github.com/yamcs/yamcs/commit/a8fb4a0693fa62a6eb729b26016d1090dd8b289c
- 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-2026-40057 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
- TI-2026-32532 Yamcs: Server-Side Code Injection (RCE) via Janino Expression Engine in `JavaExprAlgorithmExecutionFactory` CVSS 3.1CRITICAL 9.1
Sources
- CVE-2026-55565 · CVE Program
- CVE-2026-55565 · NVD
- FIRST EPSS
- GHSA-c64q-hj4j-375f · GitHub Advisory Database · CC BY 4.0
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