CVE-2026-39976
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).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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
- 7.1 HIGHCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
- EPSS
- 0.29% probability · 21th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-287
- Affected
- laravel/passport
- Source
- security-advisories@github.com
References
- https://github.com/laravel/passport/issues/1900Exploit, Issue Tracking
- https://github.com/laravel/passport/pull/1901Issue Tracking, Patch
- https://github.com/laravel/passport/pull/1902Issue Tracking, Patch
- https://github.com/laravel/passport/security/advisories/GHSA-349c-2h2f-mxf6Mitigation, Vendor Advisory
- https://github.com/thephpleague/oauth2-server/issues/1456#issuecomment-2734989996Issue Tracking, Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.