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Fencer Intel
medium 5.3

CVE-2026-125121 json

compose-lint: Text in a pull request can still issue CI workflow commands through compose-lint 0.31.0's output

published yesterday modified yesterday also EUVD-2026-121399 , GHSA-r7j4-crjv-h467

cvss
5.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 35%
public exploits
0
none known

Summary

compose-lint is a Docker Compose security linter that identifies dangerous misconfigurations before deployment. In version 0.31.0, compose-lint escapes GitHub Actions workflow-command openers only after ASCII spaces and tabs, while the runner strips all leading Unicode whitespace before interpreting a line. Untrusted Compose values or repository paths beginning with Unicode whitespace followed by :: can therefore reach the text report, fix guidance, the fix dry-run diff, and stderr diagnostics as workflow commands when the package, pre-commit hook, or Docker image runs directly in CI. The GitHub Action is not affected because it disables command processing, and the flaw does not change the lint pass or fail result. This issue is fixed in version 0.32.0.

Patch / fix

  • pypi compose-lint 0.32.0

Is CVE-2026-125121 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
pypi compose-lint
>=0.31.0, <0.32.0
0.32.0

Affected products

  • tmatens compose-lint

Classification

Weakness
  • CWE-117 Improper Output Neutralization for Logs
  • CWE-150 Improper Neutralization of Escape, Meta, or Control Sequences

References

Sources

Fencer Intel 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.