# Yamcs vulnerable to authenticated remote code execution via unescaped StreamSQL \`LIKE\` pattern compiled by Janino (\`LikeExpression\`)

Advisory record · `GHSA-c64q-hj4j-375f`

- **Identifiers:** `GHSA-c64q-hj4j-375f` · `CVE-2026-55565`
- **State:** Confirmed
- **Severity:** CVSS 9.9 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-94](https://cwe.mitre.org/data/definitions/94.html)
- **Tags:** [Code injection](https://agentprime.io/advisories/tag/code-injection.md)
- **Published:** 28 Aug 2026
- **Updated:** 28 Aug 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 28 Aug 2026, 17:30 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Critical

Critical, because:

- CVSS score 9.9: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected packages

- `org.yamcs:yamcs-core` (Maven): affected `>=5.13.0, <5.13.2 || <5.12.8`; fixed in `5.13.2`, `5.12.8`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Yamcs (org.yamcs:yamcs-core) versions 5.13.0 up to but not including 5.13.2, and versions below 5.12.8, are vulnerable. An authenticated user with a read-only archive privilege, such as ReadEvents, ReadTables, or ReadActivities, can send a LIKE pattern containing a double quote to break out of the generated Java code. This allows arbitrary OS command execution as the user running Yamcs. Upgrade to 5.13.2 or 5.12.8, which contain fixes.

Written 2 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 9.9 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0065, the 51st percentile, on 10 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:19 UTC: First seen by agentprime
- 31 Oct 2026, 14:19 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-c64q-hj4j-375f)

## Sources

- [GitHub Advisory Database: GHSA-c64q-hj4j-375f](https://github.com/advisories/GHSA-c64q-hj4j-375f)
- [OSV: GHSA-c64q-hj4j-375f](https://osv.dev/vulnerability/GHSA-c64q-hj4j-375f)
- <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>
- <https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.8>
- <https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.2>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-c64q-hj4j-375f>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-c64q-hj4j-375f/>. Everything for agents: <https://agentprime.io/llms.txt>.