CVE-2026-73421

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 61% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: None knownExposed: 0

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

NextAuth.js provides authentication for Next.js. From next-auth 5.0.0-beta.0 until 5.0.0-beta.32, applications that gate access by checking only for the existence of the auth object returned by the auth() wrapper can fail open when Auth.js has a server configuration error. In middleware, Route Handlers, React Server Components, and other auth() entry points, a non-OK session response is parsed into a truthy error object instead of null, so checks such as !!auth and if (req.auth) evaluate to true for unauthenticated requests. A provider missing both the issuer and authorization endpoint triggers InvalidEndpoints, and an unset AUTH_SECRET or another server configuration error can produce the same behavior. There is no impact while configuration is valid, but after a deployment becomes misconfigured, routes protected only by session existence silently grant access to every visitor. This issue is fixed in next-auth 5.0.0-beta.32.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
56(Track)
EG Risk 56/100SSVC: 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
Severity91% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
39%
KEV
Not listed

Published

July 23, 2026

Last Modified

September 18, 2026

Advisory Details (3)

Auto-updated Sep 15, 2026
Patch available. Sources: github_commit, github_release, github.
github Patch Available

Configuration errors can cause existence-based auth checks to fail open (auth object populated with an error) · Advisory · nextauthjs/next-auth · GitHub

https://github.com/nextauthjs/next-auth/security/advisories/GHSA-8fpg-xm3f-6cx3
github_release Patch Available

[email protected]

Patch available: nextauthjs/next-auth [email protected] (pre-release)

https://github.com/nextauthjs/next-auth/releases/tag/[email protected]
github_commit Patch Available

commit d008b9b764bf (nextauthjs/next-auth)

Patch available: nextauthjs/next-auth @auth/[email protected] (contains commit d008b9b764bf)

https://github.com/nextauthjs/next-auth/commit/d008b9b764bf4b322a87e1822d1dda7789258d8f

Vendor Advisories for CVE-2026-73421(1)

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

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
next-auth—5.0.0-beta.32—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 50× 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. 2026-09-18 20:11 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 03:06 UTCEG score recompute
  4. 2026-09-17 02:02 UTCEG score recompute
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 06:47 UTCEG score recompute
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-15 03:12 UTCEPSS rescore
  9. 2026-09-13 22:22 UTCEG score recompute
  10. 2026-09-12 19:17 UTCEG score recompute
  11. 2026-09-12 15:02 UTCEPSS rescore
  12. 2026-09-11 16:45 UTCEG score recompute
  13. 2026-09-11 14:53 UTCEPSS rescore
  14. 2026-09-10 15:10 UTCEG score recompute
  15. 2026-09-10 09:35 UTCEPSS rescore
  16. 2026-09-09 08:56 UTCEG score recompute
  17. 2026-09-08 22:01 UTCEPSS rescore
  18. 2026-09-07 21:30 UTCEG score recompute
  19. 2026-09-06 17:35 UTCEG score recompute
  20. 2026-09-06 13:48 UTCEPSS rescore
  21. 2026-09-05 19:28 UTCEG score recompute
  22. 2026-09-04 17:42 UTCEG score recompute
  23. 2026-09-04 13:16 UTCEG score recompute
  24. 2026-09-04 05:07 UTCEPSS rescore
  25. 2026-09-02 14:12 UTCEPSS rescore
Show 44 more
  1. 2026-09-01 23:22 UTCEG score recompute
  2. 2026-09-01 13:54 UTCEPSS rescore
  3. 2026-09-01 04:40 UTCEPSS rescore
  4. 2026-09-01 04:40 UTCEPSS rescore
  5. 2026-08-30 19:19 UTCEG score recompute
  6. 2026-08-30 19:18 UTCEPSS rescore
  7. 2026-08-30 19:17 UTCEPSS rescore
  8. 2026-08-30 04:58 UTCEG score recompute
  9. 2026-08-30 01:22 UTCEPSS rescore
  10. 2026-08-30 00:33 UTCEG score recompute
  11. 2026-08-28 21:42 UTCEPSS rescore
  12. 2026-08-27 14:46 UTCEG score recompute
  13. 2026-08-27 14:25 UTCEPSS rescore
  14. 2026-08-26 15:10 UTCEG score recompute
  15. 2026-08-26 14:47 UTCEPSS rescore
  16. 2026-08-25 16:14 UTCEG score recompute
  17. 2026-08-25 13:49 UTCEPSS rescore
  18. 2026-08-24 18:11 UTCEG score recompute
  19. 2026-08-24 12:18 UTCEG score recompute
  20. 2026-08-23 04:23 UTCEG score recompute
  21. 2026-08-23 00:19 UTCEPSS rescore
  22. 2026-08-22 01:50 UTCEG score recompute
  23. 2026-08-21 23:49 UTCEPSS rescore
  24. 2026-08-20 23:19 UTCEG score recompute
  25. 2026-08-20 22:56 UTCEPSS rescore
  26. 2026-08-19 20:33 UTCEG score recompute
  27. 2026-08-19 17:04 UTCEPSS rescore
  28. 2026-08-18 18:59 UTCEG score recompute
  29. 2026-08-18 13:49 UTCEPSS rescore
  30. 2026-08-18 13:49 UTCEPSS rescore
  31. 2026-08-18 02:21 UTCEG score recompute
  32. 2026-08-17 14:42 UTCEG score recompute
  33. 2026-08-17 13:47 UTCEPSS rescore
  34. 2026-08-16 16:41 UTCEG score recompute
  35. 2026-08-16 14:56 UTCEPSS rescore
  36. 2026-08-16 14:56 UTCEPSS rescore
  37. 2026-08-16 03:23 UTCEG score recompute
  38. 2026-08-16 02:15 UTCEPSS rescore
  39. 2026-08-15 05:19 UTCEG score recompute
  40. 2026-08-15 01:31 UTCEPSS rescore
  41. 2026-08-13 22:25 UTCEG score recompute
  42. 2026-08-13 22:09 UTCEG score recompute▲ 9.10
  43. 2026-08-13 22:09 UTCMITRE cvelistV5CVSS v3 → 9.1 · CVSS v4 → 9.1
  44. 2026-08-12 21:21 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-73421?
CVE-2026-73421 is a critical vulnerability published on July 23, 2026. NextAuth.js provides authentication for Next.js. From next-auth 5.0.0-beta.0 until 5.0.0-beta.32, applications that gate access by checking only for the existence of the auth object returned by the auth() wrapper can fail open when Auth.js has a server configuration error. In middleware, Route…
When was CVE-2026-73421 disclosed?
CVE-2026-73421 was first published in the National Vulnerability Database on July 23, 2026, with the most recent update on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-73421 actively exploited?
CVE-2026-73421 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 61.0% of all scored CVEs.
What is the CVSS score of CVE-2026-73421?
CVE-2026-73421 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-73421?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-73421, 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

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