CVE-2026-45793
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.02%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 1.02% probability · 61th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-200
- Source
- security-advisories@github.com
References
- https://github.com/composer/composer/commit/3f5e7f9fbfa541137d6d1d5643ec3b718e9d5039
- https://github.com/composer/composer/commit/65e6390c49f1a11cd8b660d81822086db51fe2d1
- https://github.com/composer/composer/commit/e66c8fdb7ff5409bd2f358c5f194038e49e93714
- 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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.