Vulnerability Description
Composer is a dependency Manager for the PHP language. Prior to 1.10.28, 2.2.28, and 2.9.8, Composer\IO\BaseIO::loadConfiguration() validates GitHub OAuth tokens with the regex ^[.A-Za-z0-9_]+$ and interpolates rejected tokens into an UnexpectedValueException; GitHub Actions GITHUB_TOKEN values using the ghs_<id>_<base64url-JWT> format can contain -, fail validation, and be disclosed to stderr or CI logs. This issue is fixed in versions 1.10.28, 2.2.28, and 2.9.8.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/composer/composer/commit/3f5e7f9fbfa541137d6d1d5643ec3b718e9d
- https://github.com/composer/composer/commit/65e6390c49f1a11cd8b660d81822086db51f
- https://github.com/composer/composer/commit/e66c8fdb7ff5409bd2f358c5f194038e49e9
- https://github.com/composer/composer/pull/12853
- https://github.com/composer/composer/pull/12855
- https://github.com/composer/composer/releases/tag/1.10.28
- https://github.com/composer/composer/releases/tag/2.2.28
- https://github.com/composer/composer/releases/tag/2.9.8
- https://github.com/composer/composer/security/advisories/GHSA-f9f8-rm49-7jv2
FAQ
What is CVE-2026-45793?
CVE-2026-45793 is a vulnerability with a CVSS score of 7.5 (HIGH). Composer is a dependency Manager for the PHP language. Prior to 1.10.28, 2.2.28, and 2.9.8, Composer\IO\BaseIO::loadConfiguration() validates GitHub OAuth tokens with the regex ^[.A-Za-z0-9_]+$ and in...
How severe is CVE-2026-45793?
CVE-2026-45793 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-45793?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.