GHSA-349c-2h2f-mxf6
Laravel Passport: TokenGuard Authenticates Unrelated User for Client Credentials Tokens
Quick fix
GHSA-349c-2h2f-mxf6 — laravel/passport: upgrade to the fixed version with the command below.
composer require laravel/passport:^13.7.1Details
### Impact Authentication Bypass for `client_credentials` tokens. the league/oauth2-server library sets the JWT sub claim to the client identifier (since there's no user). The token guard then passes this value to retrieveById() without validating it's actually a user identifier, potentially resolving an unrelated real user. Any machine-to-machine token can inadvertently authenticate as an actual user.
Usage of `EnsureClientIsResourceOwner` middleware together with `Passport::$clientUuids` set to `false`, can result in resolving the user instead, as stated in the [documentation](https://laravel.com/docs/13.x/passport#:~:text=The%20underlying%20OAuth2,client%20credentials%20token).
> The [underlying OAuth2 server](https://oauth2.thephpleague.com/database-setup/#:~:text=Please%20note%20that,the%20bearer%20token.) sets the token's sub claim to the client's identifier for client credentials tokens. By default, Passport uses UUIDs for clients, so this cannot collide with a user's integer primary key. However, if you have set Passport::$clientUuids to false, a client credentials token may inadvertently resolve a user whose ID matches the client's ID. In such cases, using this middleware cannot guarantee that the incoming token is a client credentials token.
### Patches Patched in v13.7.1
### Workarounds _Is there a way for users to fix or remediate the vulnerability without upgrading?_ Disallow usage of `client_credentials`.
### References - https://github.com/laravel/passport/issues/1900 - https://github.com/laravel/passport/pull/1901 - https://github.com/laravel/passport/pull/1902 - https://github.com/thephpleague/oauth2-server/issues/1456#issuecomment-2734989996
Are you affected?
Enter the version of the package you're using.
Affected packages
13.0.0Fixed in: 13.7.1composer require laravel/passport:^13.7.1References
- https://github.com/laravel/passport/security/advisories/GHSA-349c-2h2f-mxf6[WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2026-39976[ADVISORY]
- https://github.com/laravel/passport/issues/1900[WEB]
- https://github.com/thephpleague/oauth2-server/issues/1456#issuecomment-2734989996[WEB]
- https://github.com/laravel/passport/pull/1901[WEB]
- https://github.com/laravel/passport/pull/1902[WEB]
- https://github.com/laravel/passport[PACKAGE]