CVE-2026-45793
CVE-2026-45793 — Composer: Github Actions issued GITHUB_TOKEN disclosure in GitHub Actions logs
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.
Published Updated Sources: cvelistV5, GitHub_M
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
1%
chance of exploitation in 30 days
CVSS base
7.5
HIGH
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
None
none · proof-of-concept · active
Automatable
Yes
can an attacker script all four kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 7.5 | CVSS 3.1 | HIGH | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-200
Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.
- T1562.003Impair Defenses: Impair Command History Logging
- T1574.006Hijack Execution Flow: Dynamic Linker Hijacking
- T1574.007Hijack Execution Flow: Path Interception by PATH Environment Variable
References
9 on the record
- github.com/composer/composer/security/advisories/GHSA-f9f8-rm49-7jv2
x_refsource_CONFIRM
- github.com/composer/composer/pull/12853
x_refsource_MISC
- github.com/composer/composer/pull/12855
x_refsource_MISC
- github.com/composer/composer/commit/3f5e7f9fbfa541137d6d1d5643ec3b718e9d5039
x_refsource_MISC
- github.com/composer/composer/commit/65e6390c49f1a11cd8b660d81822086db51fe2d1
x_refsource_MISC
- github.com/composer/composer/commit/e66c8fdb7ff5409bd2f358c5f194038e49e93714
x_refsource_MISC
- github.com/composer/composer/releases/tag/1.10.28
x_refsource_MISC
- github.com/composer/composer/releases/tag/2.2.28
x_refsource_MISC
Elsewhere on this site
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.