Medium severity · published Jul 8, 2026
CVE-2026-59947
Composer: URL-embedded HTTP-Basic username leaks to verbose logs (GitHub PAT exposure)
4.7
CVSS
0.1%
EPSS
No
On KEV
Description
Composer is a dependency Manager for the PHP language. Prior to 2.2.29 and 2.10.2, when Composer is run with -vvv debug verbosity, it could print a credential embedded in the username slot of a repository or package URL, such as a GitHub Personal Access Token in https://TOKEN@host/, to debug output because AuthHelper, Url::sanitize, and ProcessExecutor did not sanitize username-only URL credentials. This issue is fixed in versions 2.2.29 and 2.10.2.
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Attack vector
Local
Complexity
High
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 2% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CO
composer · composer
>= 1.0, < 2.2.29; >= 2.3.0, < 2.10.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-59947
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-59947
github.com
https://github.com/composer/composer/commit/6bd66874ae523ecb69aca5964487a0cdfda03ef8
github.com
https://github.com/composer/composer/commit/8887ad76fbd830cb1861a2b1fd8ead78ed1fa1ec
github.com
https://github.com/composer/composer/releases/tag/2.10.2
github.com
https://github.com/composer/composer/releases/tag/2.2.29
github.com
https://github.com/composer/composer/security/advisories/GHSA-g6xq-892h-64w3
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