{"id":"CVE-2026-39976","aliases":["EUVD-2026-20970","GHSA-349c-2h2f-mxf6"],"status":"published","title":"Laravel Passport's TokenGuard Authenticates Unrelated User for Client Credentials Tokens","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.","severity":{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00294,"percentile":0.2223,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-287"],"published":"2026-04-08T19:57:55Z","modified":"2026-10-28T02:30:22Z","fixes":[{"ecosystem":"Packagist","package":"laravel/passport","fixed_in":["13.7.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"laravel/passport","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"13.7.1"}]}]},{"source":"osv","ecosystem":"Packagist","package":"laravel/passport","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"13.7.1"}]}],"versions":["v13.0.0","v13.0.1","v13.0.2","v13.0.3","v13.0.4","v13.0.5","v13.0.6","v13.1.0","v13.2.0","v13.2.1","v13.2.2","v13.3.0","v13.4.0","v13.4.1","v13.4.2","v13.4.3","v13.4.4","v13.5.0","v13.6.0","v13.7.0"]}],"products":[{"vendor":"laravel","product":"passport"}],"references":[{"url":"https://github.com/laravel/passport/security/advisories/GHSA-349c-2h2f-mxf6","tags":["x_refsource_CONFIRM","Mitigation","Vendor Advisory","advisory","web"]},{"url":"https://github.com/laravel/passport/issues/1900","tags":["x_refsource_MISC","Exploit","Issue Tracking","report","web"]},{"url":"https://github.com/thephpleague/oauth2-server/issues/1456#issuecomment-2734989996","tags":["x_refsource_MISC","Issue Tracking","Patch","report","web"]},{"url":"https://github.com/laravel/passport/pull/1901","tags":["x_refsource_MISC","Issue Tracking","Patch","fix","web"]},{"url":"https://github.com/laravel/passport/pull/1902","tags":["x_refsource_MISC","Issue Tracking","Patch","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39976","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-349c-2h2f-mxf6"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39976.json","tags":["advisory"]},{"url":"https://github.com/laravel/passport","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-39976","title":"Laravel Passport's TokenGuard Authenticates Unrelated User for Client Credentials Tokens","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.","status":"published","published":"2026-04-09T16:50:42.326Z","modified":"2026-04-09T19:31:53.801Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T14:20:02.662847Z"}],"euvd":[{"id":"EUVD-2026-20970","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.","status":"published","published":"2026-04-09T16:50:42Z","modified":"2026-04-09T19:31:53Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high"}],"updated_at":"2026-11-02T19:24:30.341772Z"}],"ghsa":[{"id":"GHSA-349c-2h2f-mxf6","title":"Laravel Passport: TokenGuard Authenticates Unrelated User for Client Credentials Tokens","description":"### Impact\nAuthentication 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.\n\n\nUsage of `EnsureClientIsResourceOwner` middleware together with `Passport::$clientUuids` set to `false`, can result in resolving the user instead, as stated in the [documentation](https://laravel.com/docs/13.x/passport#:~:text=The%20underlying%20OAuth2,client%20credentials%20token). \n\n\u003e The [underlying OAuth2 server](https://oauth2.thephpleague.com/database-setup/#:~:text=Please%20note%20that,the%20bearer%20token.) sets the token's sub claim to the client's identifier for client credentials tokens. By default, Passport uses UUIDs for clients, so this cannot collide with a user's integer primary key. However, if you have set Passport::$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.\n\n### Patches\nPatched in v13.7.1\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\nDisallow usage of `client_credentials`. \n\n\n### References\n- https://github.com/laravel/passport/issues/1900\n- https://github.com/laravel/passport/pull/1901\n- https://github.com/laravel/passport/pull/1902\n- https://github.com/thephpleague/oauth2-server/issues/1456#issuecomment-2734989996","status":"published","published":"2026-04-08T19:57:55Z","modified":"2026-04-13T17:48:47Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T14:39:53.087746Z"}],"nvd":[{"id":"CVE-2026-39976","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.","status":"published","published":"2026-04-09T17:16:31.267Z","modified":"2026-10-26T21:10:00.17Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T14:12:13.902911Z"}],"osv":[{"id":"CVE-2026-39976","title":"Laravel Passport's TokenGuard Authenticates Unrelated User for Client Credentials Tokens","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.","status":"published","published":"2026-04-09T16:50:42.326Z","modified":"2026-10-28T02:30:22.434396703Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T15:45:03.040464Z"},{"id":"GHSA-349c-2h2f-mxf6","title":"Laravel Passport: TokenGuard Authenticates Unrelated User for Client Credentials Tokens","description":"### Impact\nAuthentication 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.\n\n\nUsage of `EnsureClientIsResourceOwner` middleware together with `Passport::$clientUuids` set to `false`, can result in resolving the user instead, as stated in the [documentation](https://laravel.com/docs/13.x/passport#:~:text=The%20underlying%20OAuth2,client%20credentials%20token). \n\n\u003e The [underlying OAuth2 server](https://oauth2.thephpleague.com/database-setup/#:~:text=Please%20note%20that,the%20bearer%20token.) sets the token's sub claim to the client's identifier for client credentials tokens. By default, Passport uses UUIDs for clients, so this cannot collide with a user's integer primary key. However, if you have set Passport::$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.\n\n### Patches\nPatched in v13.7.1\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\nDisallow usage of `client_credentials`. \n\n\n### References\n- https://github.com/laravel/passport/issues/1900\n- https://github.com/laravel/passport/pull/1901\n- https://github.com/laravel/passport/pull/1902\n- https://github.com/thephpleague/oauth2-server/issues/1456#issuecomment-2734989996","status":"published","published":"2026-04-08T19:57:55Z","modified":"2026-04-13T18:11:23.408579Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N","level":"high"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T15:46:35.050232Z"}]}}