Composer arbitrary command execution via a malicious package's Perforce source URL
High-risk advisory
CVE-2026-84361
Summary
Composer arbitrary command execution via a malicious package's Perforce source URL
Why it matters
GitHub has published a reviewed security advisory for composer/composer. Prioritize it with other application dependency updates, especially because EPSS places it in the 34% percentile.
Operator check
Check whether composer/composer is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available. CVSS score: 7.7. EPSS probability: 0.4%; percentile: 34%.
Sources
PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.