CVE-2026-39976

HIGH

Laravel Passport's TokenGuard Authenticates Unrelated User for Client Credentials Tokens

Title source: cna
STIX 2.1

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.

References (5)

Core 5
Core References
X_Refsource_Misc x_refsource_misc
https://github.com/laravel/passport/issues/1900
X_Refsource_Misc x_refsource_misc
https://github.com/laravel/passport/pull/1901
X_Refsource_Misc x_refsource_misc
https://github.com/laravel/passport/pull/1902

Scores

CVSS v3 7.1
EPSS 0.0029
EPSS Percentile 20.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-287
Status published
Products (3)
laravel/passport 13.0.0 - 13.7.1Packagist
laravel/passport 13.0.0 - 13.7.1
laravel/passport >= 13.0.0, < 13.7.1
Published Apr 09, 2026
Tracked Since Apr 09, 2026