CVE-2026-73683 is a high-severity (CVSS 8.1) CWE-294 vulnerability. O3 Security confirms whether CVE-2026-73683 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Laravel Socialite's Facebook provider contains an authentication bypass vulnerability that allows unauthenticated attackers to replay captured OIDC id_tokens by exploiting the missing…
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-73683 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-73683 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-73683. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-73683 in your dependencies?
O3 detects CVE-2026-73683 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.