Vulnerability · Published Aug 14, 2026 · Assigned by VulnCheck

CVE-2026-73683Laravel Socialite Facebook Provider Authentication Bypass via Nonce Replay

High 8.1

In plain English

A high-severity security flaw in Socialite from Laravel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 55% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.8%top 44.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Laravel Socialite's Facebook provider contains an authentication bypass vulnerability that allows unauthenticated attackers to replay captured OIDC id_tokens by exploiting the missing nonce claim validation in the getUserByOIDCToken() function within FacebookProvider.php. Attackers who obtain a valid, unexpired id_token issued for the same Facebook App ID can submit the captured token to the backend userFromToken() endpoint, bypassing authentication controls because signature, aud, and iss checks pass while no session-bound nonce comparison is performed, resulting in unauthorized access to victim accounts.

Affected products (as reported)

Vendor	Product	Versions
Laravel	Socialite	0 – before 5.29.0

Weakness: CWE-294 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Pull Request product
Patch Commit patch
Product Repository vendor-advisory
https://www.vulncheck.com/advisories/laravel-socialite-facebook-provider-authentication-bypass-via-nonce-replay third-party-advisory