Composer: Tokens in Repository URLs Leak Into -vvv Debug Logs

Published as "Composer: URL-embedded HTTP-Basic username leaks to verbose logs (GitHub PAT exposure)"

medium Composer · Last reviewed Nov 3, 2026

CVE: CVE-2026-59947
GHSA: GHSA-g6xq-892h-64w3
Packagist: PKSA-4pm6-g63v-5rkr
Reported: Jul 20, 2026

Exposes access tokens placed in the username part of a repository URL to anyone who can read Composer's -vvv debug output.

Affected and fixed versions

In composer/composer. Find the row for the version you run, and update to the release next to it.

If you run	Update to	Support
2.3.0 – 2.10.1	2.10.2	Supported

Show 1 older branch, no longer supported

1.0.0 – 2.2.28

2.2.29

Upgrade

Run the line for the branch you are on.

composer require composer/composer:^2.10.2

What this means

Composer could print an access token in full when run with -vvv, its most detailed debug output. It already hid passwords in repository and package URLs, but not the username part. Services like GitHub let you put a token there, as in https://[email protected]/owner/repo, so the token could end up in a log.

Only people who can read that debug output see the token.

Who is affected

The Composer advisory says you're only exposed when all of these are true:

A token sits in the username part of a URL Composer uses, for example in a repositories entry, rather than in auth.json or COMPOSER_AUTH.
You run Composer with -vvv.
That output is kept or shared, such as in public CI logs or pasted into an issue.

The most likely case is a GitHub personal access token in a URL on a CI machine that saves verbose output.

What to do

Update composer/composer to 2.10.2, or to 2.2.29 if you stay on 2.2. The fix hides the username the same way as the password. Until you can update, don't run -vvv where output is saved, and move tokens into auth.json or COMPOSER_AUTH. Clean up old CI logs that may hold a token, and replace any token that leaked.

Reported by iliaal.

Check your app with an agent

Paste this into a coding agent that can read your project, such as Claude Code, Codex or Amp. It checks your composer.lock against the versions above and tells you what to update, without changing anything.

Check whether the PHP project you have access to is affected by this security advisory, and tell me what to update. Do a read-only check: don't edit files, don't run composer update or composer require, and don't try to reproduce the flaw.

Advisory: Composer: Tokens in Repository URLs Leak Into -vvv Debug Logs (CVE-2026-59947, GHSA-g6xq-892h-64w3)
Details: https://phpnews.net/security/composer/ghsa-g6xq-892h-64w3

Affected versions, as Composer constraints:
- composer/composer: >=1.0.0,<2.2.29|>=2.3.0,<2.10.2

Fixed releases on branches that still get security fixes:
- 2.3.0 – 2.10.1: update to 2.10.2

1. Find every composer.lock in the project outside vendor/ (a monorepo can have one per app) and read the installed version of each package above. Packages installed as dependencies of other packages count too.
2. Compare each installed version with its constraint: "|" separates alternative ranges, and "," means both bounds apply.
3. For each affected install, read "What this means" at https://phpnews.net/security/composer/ghsa-g6xq-892h-64w3 and check whether the project meets the conditions it describes (a feature in use, a config value, a driver). Say which conditions you could check and which you couldn't.
4. Report a table: lock file | package | installed version | affected (yes, no or unknown) | conditions met (yes, no or unknown) | update to | evidence. For each affected package, give the command that would fix it, without running it: composer update <package> --with-dependencies when it is only installed as a dependency of another package, or composer require with the fixed version when composer.json requires it directly. If the installed version is on a branch with no fixed release listed, say it needs a move to a newer branch.

Sources

← All Composer advisories