CVE-2026-44351

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 85% 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, nvd
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.1Exploit: NoneExposed: 0

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

fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.4, a critical authentication-bypass vulnerability in fast-jwt's async key-resolver flow allows any unauthenticated attacker to forge arbitrary JWTs that are accepted as authentic. When the application's key resolver returns an empty string (''), for example via the common keys[decoded.header.kid] || '' JWKS-style fallback, fast-jwt converts it to a zero-length Buffer, hands it to crypto.createSecretKey, derives allowedAlgorithms = ['HS256','HS384','HS512'] from it, and then verifies the token's signature against an empty-key HMAC. The attacker simply computes HMAC-SHA256(key='', input='${header}.${payload}'), which Node accepts without complaint — and the verifier returns the attacker-chosen payload (sub, admin, scopes, etc.) as authentic. This vulnerability is fixed in 6.2.4.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
—
EPSS
14.7%
KEV
Not listed

Published

May 13, 2026

Last Modified

May 14, 2026

Advisory Details (1)

Auto-updated May 13, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Empty HMAC secret accepted via async key resolver - JWT auth bypass · Advisory · nearform/fast-jwt · GitHub

https://github.com/nearform/fast-jwt/security/advisories/GHSA-gmvf-9v4p-v8jc

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
fast-jwt—6.2.4—

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 31× 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. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:24 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:31 UTCEPSS rescore
  5. 2026-07-19 02:29 UTCEPSS rescore
  6. 2026-07-18 10:04 UTCEPSS rescore
  7. 2026-07-18 02:29 UTCOSV refresh
  8. 2026-07-16 17:03 UTCEPSS rescore
  9. 2026-07-15 16:57 UTCEPSS rescore
  10. 2026-07-15 02:00 UTCEPSS rescore
  11. 2026-07-13 22:30 UTCEPSS rescore
  12. 2026-07-13 06:13 UTCEPSS rescore
  13. 2026-07-12 05:46 UTCEPSS rescore
  14. 2026-07-11 08:27 UTCEPSS rescore
  15. 2026-07-09 19:10 UTCEPSS rescore
  16. 2026-07-08 15:16 UTCEPSS rescore
  17. 2026-07-07 13:46 UTCEPSS rescore
  18. 2026-07-06 16:27 UTCEPSS rescore
  19. 2026-07-06 02:23 UTCEPSS rescore
  20. 2026-07-05 02:30 UTCEPSS rescore
  21. 2026-07-04 06:31 UTCEPSS rescore
  22. 2026-07-01 15:07 UTCEPSS rescore
  23. 2026-06-30 23:22 UTCEPSS rescore
  24. 2026-06-29 14:06 UTCEPSS rescore
  25. 2026-06-28 14:07 UTCEPSS rescore
Show 54 more
  1. 2026-06-28 04:56 UTCEPSS rescore
  2. 2026-06-27 03:08 UTCEPSS rescore
  3. 2026-06-25 13:49 UTCEPSS rescore
  4. 2026-06-25 13:49 UTCEPSS rescore
  5. 2026-06-24 14:05 UTCEPSS rescore
  6. 2026-06-23 21:33 UTCEPSS rescore
  7. 2026-06-22 14:25 UTCEPSS rescore
  8. 2026-06-22 14:25 UTCEPSS rescore
  9. 2026-06-21 14:56 UTCEPSS rescore
  10. 2026-06-21 14:56 UTCEPSS rescore
  11. 2026-06-21 01:59 UTCEPSS rescore
  12. 2026-06-19 19:25 UTCEPSS rescore
  13. 2026-06-18 17:52 UTCEPSS rescore
  14. 2026-06-18 17:52 UTCEPSS rescore
  15. 2026-06-17 17:53 UTCEPSS rescore
  16. 2026-06-16 17:52 UTCEPSS rescore
  17. 2026-06-15 17:49 UTCEPSS rescore
  18. 2026-06-13 23:00 UTCEPSS rescore
  19. 2026-06-12 23:12 UTCEPSS rescore
  20. 2026-06-12 23:12 UTCEPSS rescore
  21. 2026-06-11 14:00 UTCEPSS rescore
  22. 2026-06-10 22:18 UTCEPSS rescore
  23. 2026-06-10 13:22 UTCEPSS rescore
  24. 2026-06-10 13:22 UTCEPSS rescore
  25. 2026-06-08 14:17 UTCEPSS rescore
  26. 2026-06-08 14:17 UTCEPSS rescore
  27. 2026-06-07 15:25 UTCEPSS rescore
  28. 2026-06-07 15:25 UTCEPSS rescore
  29. 2026-06-06 13:47 UTCEPSS rescore
  30. 2026-06-06 13:47 UTCEPSS rescore
  31. 2026-06-05 22:47 UTCEPSS rescore
  32. 2026-06-05 06:10 UTCEPSS rescore
  33. 2026-06-05 06:10 UTCEPSS rescore
  34. 2026-06-04 13:12 UTCEPSS rescore
  35. 2026-06-04 13:12 UTCEPSS rescore
  36. 2026-06-02 20:13 UTCEPSS rescore
  37. 2026-06-01 13:52 UTCEPSS rescore
  38. 2026-06-01 13:52 UTCEPSS rescore
  39. 2026-05-31 22:30 UTCEPSS rescore
  40. 2026-05-31 22:30 UTCEPSS rescore
  41. 2026-05-31 00:16 UTCEPSS rescore
  42. 2026-05-31 00:16 UTCEPSS rescore
  43. 2026-05-29 13:44 UTCEPSS rescore
  44. 2026-05-29 13:44 UTCEPSS rescore
  45. 2026-05-28 13:44 UTCEPSS rescore
  46. 2026-05-28 13:44 UTCEPSS rescore
  47. 2026-05-27 13:40 UTCEPSS rescore
  48. 2026-05-27 13:40 UTCEPSS rescore
  49. 2026-05-26 13:44 UTCEPSS rescore
  50. 2026-05-26 07:18 UTCEPSS rescore
  51. 2026-05-21 22:43 UTCEPSS rescore
  52. 2026-05-20 22:38 UTCEPSS rescore
  53. 2026-05-20 12:24 UTCEG score recompute
  54. 2026-05-20 11:22 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-44351?
CVE-2026-44351 is a critical vulnerability published on May 13, 2026. fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.4, a critical authentication-bypass vulnerability in fast-jwt's async key-resolver flow allows any unauthenticated attacker to forge arbitrary JWTs that are accepted as authentic. When the application's key resolver returns an…
When was CVE-2026-44351 disclosed?
CVE-2026-44351 was first published in the National Vulnerability Database on May 13, 2026, with the most recent update on May 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-44351 actively exploited?
CVE-2026-44351 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 14.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-44351?
CVE-2026-44351 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-44351?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-44351, 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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