CVE-2026-35040

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 60% 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
Elevated
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: 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 6.2.1, using certain modifiers on RegExp objects in the allowedAud, allowedIss, allowedSub, allowedJti, or allowedNonce options in verify functions can cause certain unintended behaviours. This is because some modifiers are stateful and will cause failures in every second verification attempt regardless of the validity of the token provided. Such modifiers are /g (global matching) and /y (sticky matching). This does NOT allow invalid tokens to be accepted, only for valid tokens to be improperly rejected in some configurations. Instead it causes 50% of valid authentication requests to fail in an alternating pattern. This vulnerability is fixed in 6.2.1.

CVSS v3
5.3
EG Score
5.3(medium)
EPSS
30.8%
KEV
Not listed

Published

April 9, 2026

Last Modified

April 17, 2026

References (4)

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
fast-jwt—6.2.1—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 38× 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 20:02 UTCOSV refresh
  4. 2026-07-20 17:08 UTCEPSS rescore
  5. 2026-07-19 14:31 UTCEPSS rescore
  6. 2026-07-19 02:29 UTCEPSS rescore
  7. 2026-07-18 10:04 UTCEPSS rescore
  8. 2026-07-16 17:03 UTCEPSS rescore
  9. 2026-07-15 16:57 UTCEPSS rescore
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 02:00 UTCEPSS rescore
  12. 2026-07-13 22:30 UTCEPSS rescore
  13. 2026-07-13 06:13 UTCEPSS rescore
  14. 2026-07-13 06:13 UTCEPSS rescore
  15. 2026-07-12 05:46 UTCEPSS rescore
  16. 2026-07-11 08:27 UTCEPSS rescore
  17. 2026-07-09 19:10 UTCEPSS rescore
  18. 2026-07-08 15:15 UTCEPSS rescore
  19. 2026-07-07 13:46 UTCEPSS rescore
  20. 2026-07-06 16:27 UTCEPSS rescore
  21. 2026-07-06 16:27 UTCEPSS rescore
  22. 2026-07-06 02:23 UTCEPSS rescore
  23. 2026-07-06 02:23 UTCEPSS rescore
  24. 2026-07-04 06:31 UTCEPSS rescore
  25. 2026-07-01 15:06 UTCEPSS rescore
Show 67 more
  1. 2026-06-30 23:22 UTCEPSS rescore
  2. 2026-06-29 14:06 UTCEPSS rescore
  3. 2026-06-29 14:06 UTCEPSS rescore
  4. 2026-06-28 14:07 UTCEPSS rescore
  5. 2026-06-28 14:07 UTCEPSS rescore
  6. 2026-06-28 04:56 UTCEPSS rescore
  7. 2026-06-28 04:56 UTCEPSS rescore
  8. 2026-06-27 03:08 UTCEPSS rescore
  9. 2026-06-25 13:49 UTCEPSS rescore
  10. 2026-06-25 13:49 UTCEPSS rescore
  11. 2026-06-24 14:05 UTCEPSS rescore
  12. 2026-06-23 21:33 UTCEPSS rescore
  13. 2026-06-23 21:33 UTCEPSS rescore
  14. 2026-06-22 14:25 UTCEPSS rescore
  15. 2026-06-22 14:25 UTCEPSS rescore
  16. 2026-06-21 14:56 UTCEPSS rescore
  17. 2026-06-21 14:56 UTCEPSS rescore
  18. 2026-06-21 01:59 UTCEPSS rescore
  19. 2026-06-19 19:25 UTCEPSS rescore
  20. 2026-06-19 19:25 UTCEPSS rescore
  21. 2026-06-18 17:52 UTCEPSS rescore
  22. 2026-06-18 17:52 UTCEPSS rescore
  23. 2026-06-17 17:53 UTCEPSS rescore
  24. 2026-06-16 17:52 UTCEPSS rescore
  25. 2026-06-15 17:49 UTCEPSS rescore
  26. 2026-06-14 23:18 UTCEPSS rescore
  27. 2026-06-13 23:00 UTCEPSS rescore
  28. 2026-06-12 23:12 UTCEPSS rescore
  29. 2026-06-12 23:12 UTCEPSS rescore
  30. 2026-06-11 14:00 UTCEPSS rescore
  31. 2026-06-10 22:18 UTCEPSS rescore
  32. 2026-06-10 13:22 UTCEPSS rescore
  33. 2026-06-08 14:17 UTCEPSS rescore
  34. 2026-06-08 14:17 UTCEPSS rescore
  35. 2026-06-07 15:25 UTCEPSS rescore
  36. 2026-06-07 15:25 UTCEPSS rescore
  37. 2026-06-07 15:25 UTCEPSS rescore
  38. 2026-06-06 13:47 UTCEPSS rescore
  39. 2026-06-06 13:47 UTCEPSS rescore
  40. 2026-06-05 22:47 UTCEPSS rescore
  41. 2026-06-05 22:47 UTCEPSS rescore
  42. 2026-06-05 06:10 UTCEPSS rescore
  43. 2026-06-05 06:10 UTCEPSS rescore
  44. 2026-06-04 13:12 UTCEPSS rescore
  45. 2026-06-04 13:12 UTCEPSS rescore
  46. 2026-06-02 20:13 UTCEPSS rescore
  47. 2026-06-01 13:52 UTCEPSS rescore
  48. 2026-06-01 13:52 UTCEPSS rescore
  49. 2026-06-01 13:51 UTCEPSS rescore
  50. 2026-05-31 22:30 UTCEPSS rescore
  51. 2026-05-31 22:30 UTCEPSS rescore
  52. 2026-05-29 13:44 UTCEPSS rescore
  53. 2026-05-29 13:44 UTCEPSS rescore
  54. 2026-05-28 13:44 UTCEPSS rescore
  55. 2026-05-28 13:44 UTCEPSS rescore
  56. 2026-05-28 13:44 UTCEPSS rescore
  57. 2026-05-27 13:40 UTCEPSS rescore
  58. 2026-05-27 13:40 UTCEPSS rescore
  59. 2026-05-27 13:40 UTCEPSS rescore
  60. 2026-05-26 13:44 UTCEPSS rescore
  61. 2026-05-26 07:18 UTCEPSS rescore
  62. 2026-05-26 07:18 UTCEPSS rescore
  63. 2026-05-20 22:38 UTCEPSS rescore
  64. 2026-05-20 22:38 UTCEPSS rescore
  65. 2026-05-20 18:06 UTCEG score recompute
  66. 2026-05-20 11:22 UTCEPSS rescore
  67. 2026-05-20 11:22 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-35040?
CVE-2026-35040 is a medium vulnerability published on April 9, 2026. fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.1, using certain modifiers on RegExp objects in the allowedAud, allowedIss, allowedSub, allowedJti, or allowedNonce options in verify functions can cause certain unintended behaviours. This is because some modifiers are…
When was CVE-2026-35040 disclosed?
CVE-2026-35040 was first published in the National Vulnerability Database on April 9, 2026, with the most recent update on April 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-35040 actively exploited?
CVE-2026-35040 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 30.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-35040?
CVE-2026-35040 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-35040?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-35040, 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.

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