CVE-2026-45793

high

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.

References

https://github.com/composer/composer/security/advisories/GHSA-f9f8-rm49-7jv2

https://github.com/composer/composer/releases/tag/2.9.8

https://github.com/composer/composer/releases/tag/2.2.28

https://github.com/composer/composer/releases/tag/1.10.28

https://github.com/composer/composer/pull/12855

https://github.com/composer/composer/pull/12853

https://github.com/composer/composer/commit/e66c8fdb7ff5409bd2f358c5f194038e49e93714

https://github.com/composer/composer/commit/65e6390c49f1a11cd8b660d81822086db51fe2d1

https://github.com/composer/composer/commit/3f5e7f9fbfa541137d6d1d5643ec3b718e9d5039

Details

Source: Mitre, NVD

Published: 2026-07-15

Updated: 2026-07-15

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:N

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Severity: High

EPSS

EPSS: 0.0006