CVE-2026-39976 — HIGH (7.1)

Vulnerability 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 Score

7.1

HIGH

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality

HIGH

Integrity

LOW

Availability

NONE

Related Weaknesses (CWE)

CWE-287

References

FAQ

What is CVE-2026-39976?

CVE-2026-39976 is a vulnerability with a CVSS score of 7.1 (HIGH). 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...

How severe is CVE-2026-39976?

CVE-2026-39976 has been rated HIGH with a CVSS base score of 7.1/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-39976?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.