CVE-2026-39976 json
Laravel Passport's TokenGuard Authenticates Unrelated User for Client Credentials Tokens
published 2026-04-08 7 mo ago modified 2026-10-26 13 d ago also EUVD-2026-20970 , GHSA-349c-2h2f-mxf6
- cvss
- 7.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 22%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- packagist laravel/passport 13.7.1
- passport_project passport 13.7.1
- github.com/thephpleague/oauth2-server/issues/1456#issuecomment-273498… patch
- github.com/laravel/passport#1901 pull request
- github.com/laravel/passport#1902 pull request
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 7 mo ago
Exploit prediction
0.29% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/laravel/passport/issues/1900 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N |
| GitHub | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | laravel/passport | >=13.0.0, <13.7.1 |
13.7.1 |
Affected products
- laravel passport
Classification
- Weakness
-
- CWE-287 Improper Authentication
References
-
github.com
/laravel/passport/pull/1901
web, issue-tracking, patch
-
github.com
/laravel/passport/pull/1902
web, issue-tracking, patch
-
github.com
/thephpleague/oauth2-server/issues/1456#issuecomment-2734989996
web, issue-tracking, patch
-
github.com
/laravel/passport/issues/1900
web, exploit, issue-tracking
-
github.com
/laravel/passport/security/advisories/GHSA-349c-2h2f-mxf6
web, mitigation, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-39976
advisory
-
github.com
/laravel/passport
package
Sources
- CVE List CVE-2026-39976
- GitHub Advisory GHSA-349c-2h2f-mxf6
- NVD CVE-2026-39976
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.