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Vulnerability · Published Apr 9, 2026 · Assigned by GitHub_M

CVE-2026-39976Laravel Passport's TokenGuard Authenticates Unrelated User for Client Credentials Tokens

High 7.1

In plain English

A high-severity improper authentication in passport from laravel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.1High
Exploit odds (30 days)0.3%top 77.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Packagistlaravel/passport13.7.1GHSA-349c-2h2f-mxf6

Affected products (as reported)

VendorProductVersions
laravel passport >= 13.0.0, < 13.7.1

Weakness: CWE-287 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N

References