High 7.5Published Jul 15, 2026

CVE-2026-45793Composer: Github Actions issued GITHUB_TOKEN disclosure in GitHub Actions logs

Updated under an hour ago (Oct 27, 2026, 5:20 PM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness (CWE): CWE-200
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Awaiting Analysis
Record last updated: Jul 15, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

composer composer composer:composer (from the name)	from 1.0, < 1.10.28; from 2.0.0, < 2.2.28; from 2.3.0, < 2.9.8	CNA record

References

References

https://github.com/composer/composer/security/advisories/GHSA-f9f8-rm49-7jv2	x-refsource-confirm
https://github.com/composer/composer/pull/12853	x-refsource-misc
https://github.com/composer/composer/pull/12855	x-refsource-misc
https://github.com/composer/composer/commit/3f5e7f9fbfa541137d6d1d5643ec3b718e9d5039	x-refsource-misc
https://github.com/composer/composer/commit/65e6390c49f1a11cd8b660d81822086db51fe2d1	x-refsource-misc
https://github.com/composer/composer/commit/e66c8fdb7ff5409bd2f358c5f194038e49e93714	x-refsource-misc
https://github.com/composer/composer/releases/tag/1.10.28	x-refsource-misc
https://github.com/composer/composer/releases/tag/2.2.28	x-refsource-misc
https://github.com/composer/composer/releases/tag/2.9.8	x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.