CVE-2026-39976
Laravel Passport's TokenGuard Authenticates Unrelated User for Client Credentials Tokens
Laravel Passport provides OAuth2 server support to Laravel. From 13.0.0 to before 13.7.1, there is an 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. This vulnerability is fixed in 13.7.1.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
Affected products
laravel · passportWant to know if your infrastructure is exposed to this?
Talk to TrueHacking →References
https://github.com/laravel/passport/issues/1900https://github.com/laravel/passport/pull/1901https://github.com/laravel/passport/pull/1902https://github.com/laravel/passport/security/advisories/GHSA-349c-2h2f-mxf6https://github.com/thephpleague/oauth2-server/issues/1456#issuecomment-2734989996