CVE-2026-73683

HIGHPre-NVD 8.18.1—
EchelonGraph scoreHIGH confidence

Score 8.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-15. a secondary CVSS source baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a 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 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.

CVSS v3
8.1
EG Score
8.1(high)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity81% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
37%
KEV
Not listed

Published

August 14, 2026

Last Modified

August 18, 2026

Advisory Details (4)

Auto-updated Aug 14, 2026
Upstream fix merged — awaiting tagged release. Sources: github_pr, github_commit.
generic

Laravel Socialite Facebook Provider Authentication Bypass via Nonce Replay | Advisories | VulnCheck

https://www.vulncheck.com/advisories/laravel-socialite-facebook-provider-authentication-bypass-via-nonce-replay
generic

GitHub - laravel/socialite: Laravel wrapper around OAuth 1 & OAuth 2 libraries. · GitHub

https://github.com/laravel/socialite
github_commit

commit caf714f55d51 (laravel/socialite)

Fix landed in laravel/socialite commit caf714f55d51 — awaiting tagged release

https://github.com/laravel/socialite/commit/caf714f55d51ab0d914b40033d8b0f489d6219cc
github_pr

fix: Validate Facebook OIDC token nonce

Fix merged in laravel/socialite PR #789 on 2026-08-13 — awaiting tagged release

https://github.com/laravel/socialite/pull/789

Vendor Advisories for CVE-2026-73683(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 34× in last 7d / 34× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-21 04:26 UTCEG score recompute
  2. 2026-08-21 04:26 UTCGHSA enrichment
  3. 2026-08-20 22:56 UTCEPSS rescore
  4. 2026-08-20 16:16 UTCGHSA enrichment
  5. 2026-08-20 04:06 UTCEG score recompute
  6. 2026-08-20 04:06 UTCGHSA enrichment
  7. 2026-08-19 17:04 UTCEPSS rescore
  8. 2026-08-19 15:57 UTCGHSA enrichment
  9. 2026-08-19 03:46 UTCGHSA enrichment
  10. 2026-08-18 15:36 UTCEG score recompute
  11. 2026-08-18 15:36 UTCGHSA enrichment
  12. 2026-08-18 13:49 UTCEPSS rescore
  13. 2026-08-18 13:49 UTCEPSS rescore
  14. 2026-08-18 03:24 UTCEG score recompute
  15. 2026-08-18 03:24 UTCGHSA enrichment
  16. 2026-08-18 02:42 UTCEG score recompute
  17. 2026-08-18 02:41 UTCGHSA enrichment
  18. 2026-08-17 22:19 UTCEG score recompute
  19. 2026-08-17 22:19 UTCGHSA enrichment
  20. 2026-08-17 13:47 UTCEPSS rescore
  21. 2026-08-17 11:06 UTCGHSA enrichment
  22. 2026-08-16 22:57 UTCEG score recompute
  23. 2026-08-16 22:57 UTCGHSA enrichment
  24. 2026-08-16 14:56 UTCEPSS rescore
  25. 2026-08-16 14:56 UTCEPSS rescore
Show 9 more
  1. 2026-08-16 10:47 UTCEG score recompute
  2. 2026-08-16 10:47 UTCGHSA enrichment
  3. 2026-08-16 02:15 UTCEPSS rescore
  4. 2026-08-15 22:38 UTCGHSA enrichment
  5. 2026-08-15 10:28 UTCEG score recompute
  6. 2026-08-15 10:28 UTCGHSA enrichment
  7. 2026-08-14 22:18 UTCEG score recompute
  8. 2026-08-14 21:39 UTCEG score recompute
  9. 2026-08-14 21:38 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-73683?
CVE-2026-73683 is a high vulnerability published on August 14, 2026. Laravel Socialite's Facebook provider contains an authentication bypass vulnerability that allows unauthenticated attackers to replay captured OIDC idtokens by exploiting the missing nonce claim validation in the getUserByOIDCToken() function within FacebookProvider.php. Attackers who obtain a…
When was CVE-2026-73683 disclosed?
CVE-2026-73683 was first published in the National Vulnerability Database on August 14, 2026, with the most recent update on August 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-73683 actively exploited?
CVE-2026-73683 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 63.0% of all scored CVEs.
What is the CVSS score of CVE-2026-73683?
CVE-2026-73683 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-73683?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-73683, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-73683

Explore →

Is Your Infrastructure Affected by CVE-2026-73683?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs