CVE-2026-39976

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 v3 7.1 HIGH

7.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 4.7

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/laravel/passport/issues/1900	Exploit Issue Tracking
https://github.com/laravel/passport/pull/1901	Issue Tracking Patch
https://github.com/laravel/passport/pull/1902	Issue Tracking Patch
https://github.com/laravel/passport/security/advisories/GHSA-349c-2h2f-mxf6	Mitigation Vendor Advisory
https://github.com/thephpleague/oauth2-server/issues/1456#issuecomment-2734989996	Issue Tracking Patch

Configurations

Configuration 1 (hide)

cpe:2.3:a:laravel:passport:*:*:*:*:*:laravel:*:*

History

26 Oct 2026, 21:10

Type	Values Removed	Values Added
Summary		(es) Laravel Passport proporciona soporte de servidor OAuth2 a Laravel. Desde la 13.0.0 hasta antes de la 13.7.1, existe una omisión de autenticación para los tokens de client_credentials. La biblioteca league/oauth2-server establece la declaración sub de JWT al identificador del cliente (ya que no hay usuario). El token guard luego pasa este valor a retrieveById() sin validar que es realmente un identificador de usuario, resolviendo potencialmente un usuario real no relacionado. Cualquier token de máquina a máquina puede autenticarse inadvertidamente como un usuario real. Esta vulnerabilidad está corregida en la 13.7.1.

Information

Published : 2026-04-09 17:16

Updated : 2026-10-26 21:10

NVD link : CVE-2026-39976

Mitre link : CVE-2026-39976

CVE.ORG link : CVE-2026-39976

JSON object : View

Products Affected

laravel

passport

CWE

CWE-287

Improper Authentication

{"id": "CVE-2026-39976", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-39976", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-04-09T17:38:00.854614Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 7.1, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 4.7, "exploitabilityScore": 1.8}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "laravel", "product": "passport", "versions": [{"status": "affected", "version": ">= 13.0.0, < 13.7.1"}]}]}], "published": "2026-04-09T17:16:31.267", "references": [{"url": "https://github.com/laravel/passport/issues/1900", "tags": ["Exploit", "Issue Tracking"], "source": "security-advisories@github.com"}, {"url": "https://github.com/laravel/passport/pull/1901", "tags": ["Issue Tracking", "Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/laravel/passport/pull/1902", "tags": ["Issue Tracking", "Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/laravel/passport/security/advisories/GHSA-349c-2h2f-mxf6", "tags": ["Mitigation", "Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/thephpleague/oauth2-server/issues/1456#issuecomment-2734989996", "tags": ["Issue Tracking", "Patch"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-287"}]}], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "Laravel Passport proporciona soporte de servidor OAuth2 a Laravel. Desde la 13.0.0 hasta antes de la 13.7.1, existe una omisi\u00f3n de autenticaci\u00f3n para los tokens de client_credentials. La biblioteca league/oauth2-server establece la declaraci\u00f3n sub de JWT al identificador del cliente (ya que no hay usuario). El token guard luego pasa este valor a retrieveById() sin validar que es realmente un identificador de usuario, resolviendo potencialmente un usuario real no relacionado. Cualquier token de m\u00e1quina a m\u00e1quina puede autenticarse inadvertidamente como un usuario real. Esta vulnerabilidad est\u00e1 corregida en la 13.7.1."}], "lastModified": "2026-10-26T21:10:00.170", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:laravel:passport:*:*:*:*:*:laravel:*:*", "vulnerable": true, "matchCriteriaId": "E42FBA16-DEE3-4FAE-B8DB-2B2F62D9CDEE", "versionEndExcluding": "13.7.1", "versionStartIncluding": "13.0.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}