Log in Start free

Vulnerability · Published Jul 8, 2026 · Assigned by GitHub_M

CVE-2026-59947Composer: URL-embedded HTTP-Basic username leaks to verbose logs (GitHub PAT exposure)

Medium 4.7

In plain English

A medium-severity sensitive data in logs in composer from composer. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.7Medium
Exploit odds (30 days)0.1%top 98.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12composerno fix listedDEBIAN-CVE-2026-59947
Debian:13composerno fix listedDEBIAN-CVE-2026-59947
Debian:14composer2.10.2-1DEBIAN-CVE-2026-59947
Packagistcomposer/composer2.2.29GHSA-g6xq-892h-64w3
Packagistcomposer/composer2.10.2GHSA-g6xq-892h-64w3
Ubuntu:25.10composerno fix listedUBUNTU-CVE-2026-59947
Ubuntu:26.04:LTScomposerno fix listedUBUNTU-CVE-2026-59947
Ubuntu:26.10composerno fix listedUBUNTU-CVE-2026-59947

Affected products (as reported)

VendorProductVersions
composer composer >= 1.0, < 2.2.29>= 2.3.0, < 2.10.2

Weakness: CWE-532 · Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

References