Information disclosure in Composer
CVE-2026-59947
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.
EPSS: 0.001 (2.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Composer — versions >= 1.0, < 2.2.29, >= 2.3.0, < 2.10.2
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-59947?
- CVE-2026-59947 is a medium-severity vulnerability in Composer, classified under Insertion of Sensitive Information into Log File. CVSS score: 4.7/10. Published 2026-07-08.
- How severe is CVE-2026-59947?
- Medium severity. CVSS v3 base score is 4.7 out of 10.