CVE-2026-59947

Summary

When Composer is run with -vvv (debug verbosity), it could print a credential that was embedded directly in a repository or package URL, but not as a password, to its debug output. Composer already masked the password portion of such URLs, but the username portion was shown in clear text. Because GitHub and several other services support placing an access token in the username position of a URL (for example https://[token]@github.com/owner/repo), a token used that way could end up written to the verbose log in full.

This is an information disclosure issue. The credential is only ever exposed to whoever can already read Composer's debug output.

Am I affected?

You are potentially affected only if all of the following apply:

• A credential is embedded inside a URL that Composer handles, e.g. in a repositories entry in composer.json, in a package dist/source URL - rather than being supplied through auth.json or the COMPOSER_AUTH environment variable.
• The secret sits in the username slot of that URL (e.g. https://TOKEN@host/…). A normal username:password@host pair where the username is an ordinary account name did not expose the password, that was already masked.
• Composer is run with -vvv (debug verbosity), and that output is retained or shared somewhere others can read it: public CI build logs, output pasted into an issue or chat, archived terminal sessions, and so on.

If you keep credentials in auth.json or environment variables, or you never run Composer at debug verbosity, you were not exposed.

The most realistic exposure is the documented pattern of embedding a GitHub Personal Access Token in a URL's username position on a machine (often CI) that captures verbose output.

Patched versions

The username is now masked the same way the password already was, so an embedded token no longer appears in verbose output (a short, non-secret prefix may be shown to aid debugging, but never the full value).

Fixed in Composer 2.10.2 and the 2.2.29.

Workarounds

There is no configuration setting that prevents outputting credentials while keeping normal behavior.

If you cannot upgrade right away, you can reduce exposure by:

• Not running Composer with -vvv (debug verbosity) in environments where output is captured or shared.
• Moving credentials out of URLs and into auth.json or COMPOSER_AUTH.
• Scrubbing existing CI/build logs that may already contain a leaked token.

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.

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.

These are all security issues fixed in the php-composer2-2.10.2-1.1 package on the GA media of openSUSE Tumbleweed.

This update for php-composer2 fixes the following issues:

• CVE-2026-45793: Github Actions issued GITHUB_TOKEN disclosure in GitHub Actions logs (bsc#1271504).
• CVE-2026-59946: path traversal in package bin field lets dependencies chmod arbitrary host files (bsc#1271151).
• CVE-2026-59947: URL-embedded HTTP-Basic username leaks to verbose logs (bsc#1271129).
• CVE-2026-59948: arbitrary file write outside vendordirectory via malicious transitive package name (bsc#1271122).

Changes for php-composer2:

• fix byte-swapped signature on s390x can cause broken or unsupported signature (bsc#1271729).

This update for php-composer2 fixes the following issues:

• CVE-2026-59944: path traversal and link following issue can make files world readable and executable (bsc#1279898).

This update for php-composer2 fixes the following issues:

• CVE-2026-45793: Github Actions issued GITHUB_TOKEN disclosure in GitHub Actions logs (bsc#1271504).
• CVE-2026-59946: path traversal in package bin field lets dependencies chmod arbitrary host files (bsc#1271151).
• CVE-2026-59947: URL-embedded HTTP-Basic username leaks to verbose logs (bsc#1271129).
• CVE-2026-59948: arbitrary file write outside vendordirectory via malicious transitive package name (bsc#1271122).

Changes for php-composer2:

• fix byte-swapped signature on s390x can cause broken or unsupported signature (bsc#1271729).

This update for php-composer2 fixes the following issues:

• CVE-2026-45793: Github Actions issued GITHUB_TOKEN disclosure in GitHub Actions logs (bsc#1271504).
• CVE-2026-59946: path traversal in package bin field lets dependencies chmod arbitrary host files (bsc#1271151).
• CVE-2026-59947: URL-embedded HTTP-Basic username leaks to verbose logs (bsc#1271129).
• CVE-2026-59948: arbitrary file write outside vendordirectory via malicious transitive package name (bsc#1271122).

Changes for php-composer2:

• fix byte-swapped signature on s390x can cause broken or unsupported signature (bsc#1271729).

This update for php-composer2 fixes the following issues:

• CVE-2026-59944: path traversal and link following issue can make files world readable and executable (bsc#1279898).

This update for php-composer2 fixes the following issues:

• CVE-2026-45793: Github Actions issued GITHUB_TOKEN disclosure in GitHub Actions logs (bsc#1271504).
• CVE-2026-59946: path traversal in package bin field lets dependencies chmod arbitrary host files (bsc#1271151).
• CVE-2026-59947: URL-embedded HTTP-Basic username leaks to verbose logs (bsc#1271129).
• CVE-2026-59948: arbitrary file write outside vendordirectory via malicious transitive package name (bsc#1271122).

This update for php-composer2 fixes the following issues:

• CVE-2026-45793: GitHub OAuth tokens failing regex validation can cause credential disclosure (bsc#1271504).
• CVE-2026-59944: path traversal and link following issue can make files world readable and executable (bsc#1279898).
• CVE-2026-59946: package bin entries with path segments can cause unintended host file permission modifications (bsc#1271152).
• CVE-2026-59947: unsanitized URL credential handling in debug output within Composer can allow sensitive token disclosure (bsc#1271130).
• CVE-2026-59948: missing package name validation during dependency resolution in Composer can allow path traversal (bsc#1271123).
• CVE-2026-84361: arbitrary code execution via malicious Perforce source URL (bsc#1278257).

Changes for php-composer2:

• version update to 2.2.30:

• Fixed command injection via malicious Perforce url (GHSA-rvx4-ffvw-m9q3)
• Sanitize URL-embedded usernames/token in a few more places (#13045)
• Fixed matching of gitlab URLs to avoid possible credential leak to the wrong domain (#13042)

• fix a regression on s390x due last change (bsc#1271729).

• version update to 2.2.29:

• Validate package names (GHSA-499r-g7pc-vmp9)
• Validate package bin paths against path traversal (GHSA-gjfg-22fp-rrxx)
• Sanitize URL-embedded usernames/token in verbose output (GHSA-g6xq-892h-64w3)
• Only follow HTTP redirects from HTTP responses (#12948)
• Prevent phar metadata unserialization on unsafe PHP versions (#12946)
• Sanitize JSON parse errors in http responses to avoid leaking response body data (#12959)
• Fixed GitHub token validation to be even more relaxed (#12856)

• version update to 2.2.28.

This update for php-composer2 fixes the following issues:

• CVE-2026-59944: path traversal and link following issue can make files world readable and executable (bsc#1279898).

This update for php-composer2 fixes the following issues:

• CVE-2026-59946: package bin entries with path segments can cause unintended host file permission modifications (bsc#1271152).
• CVE-2026-59947: unsanitized URL credential handling in debug output within Composer can allow sensitive token disclosure (bsc#1271130).
• CVE-2026-59948: missing package name validation during dependency resolution in Composer can allow path traversal (bsc#1271123).