CVE-2026-45793
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure.
- Exploit odds
- 1.0% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.0% in the next 30 days (EPSS).
- Severity: 7.5 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 1.0% · EPSS, next 30 days
- Weakness
- CWE-200 · Information exposure
- Record status
- Awaiting Analysis
Attack profile CVSS 3.1 · 7.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-45793.md and follow it. Check whether this project is affected by CVE-2026-45793. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- 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
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