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Fencer Vulns
critical 9.1

CVE-2026-44632 json

Yamcs: Server-Side Code Injection (RCE) via Janino Expression Engine in `JavaExprAlgorithmExecutionFactory`

published 2026-05-27 5 mo ago modified 2026-07-17 3 mo ago also GHSA-524g-x36v-9wm6 , EUVD-2026-44957

cvss
9.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 66%
public exploits
0
none known

Summary

Yamcs is a mission control framework. Prior to 5.12.7, a server-side code injection vulnerability existed in the Yamcs algorithm evaluation engine org.yamcs.algorithms.JavaExprAlgorithmExecutionFactory, which dynamically compiled and evaluated user-controlled algorithm text through the Janino compiler without enforcing a secure sandbox, so an authenticated user with the ChangeMissionDatabase privilege could override an existing algorithm's text via the mission database REST API and inject Java code (for example using java.lang.Runtime) to achieve remote code execution on the underlying host operating system. This issue is fixed in versions 5.12.7 and 5.13.0, which disable algorithm editing by default.

Patch / fix

  • maven org.yamcs:yamcs-core 5.12.7
  • spaceapplications yamcs 5.12.7

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
3 mo ago

Exploit prediction

1.12% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
GitHub 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
maven org.yamcs:yamcs-core
<5.12.7
5.12.7

Affected products

  • yamcs yamcs

Classification

Weakness
  • CWE-94 Improper Control of Generation of Code

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.