vulnerability / NVI-00003394 / Revision 4
Composer: URL-embedded HTTP-Basic username leaks to verbose logs (GitHub PAT exposure)
GitHub lists this reviewed advisory for composer/composer, composer/composer. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
4.7 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
4.7 MEDIUM (3.1)
security-advisories@github.com severity; no combined Null risk score.
0.120%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.01809. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
composer/composer
source listed>= 2.3.0, < 2.10.2
## 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
composer/composer
source listed>= 1.0.0, < 2.2.29
## 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
composer/composer
source listedECOSYSTEM: introduced 2.3.0; fixed 2.10.2
## 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
composer/composer
source listedECOSYSTEM: introduced 1.0.0; fixed 2.2.29
## 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
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
- vendor patch
The original advisory lists fixed boundaries 2.10.2 for composer/composer. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- vendor patch
The original advisory lists fixed boundaries 2.2.29 for composer/composer. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-g6xq-892h-64w3 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- GHSA-g6xq-892h-64w3 ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
- CVE-2026-59947 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
- CVE-2026-59947 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 4 ·
Source facts changed; compare the preserved prior revision.
- Revision 3 ·
Source facts changed; compare the preserved prior revision.
- Revision 2 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.