Vulnerability in Laravel Socialite
CVE-2026-73683
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.008 (53.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 53.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.008 · change: +0.003
Affected products
- Laravel Socialite — versions 0
Weakness classification (CWE)
References
- github.com/laravel/socialite/pull/789 (product)
- github.com/laravel/socialite/commit/caf714f55d51ab0d914b40033d8b0f489d6219cc (patch)
- github.com/laravel/socialite (vendor-advisory)
- www.vulncheck.com/advisories/laravel-socialite-facebook-provider-authentication… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-73683?
- CVE-2026-73683 is a high-severity vulnerability in Laravel Socialite, classified under Authentication Bypass by Capture-replay. CVSS score: 8.1/10. Published 2026-08-14.
- How severe is CVE-2026-73683?
- High severity. CVSS v3 base score is 8.1 out of 10.