Skip to main content
VulnerabilityPublished

CVE-2026-35041: nearform fast-jwt · ReDoS

Affects nearform fast-jwtSource CVE Database V5

0
Compare

Not known to be exploited · CVSS 4.2 Medium : upgrade to 6.2.1 when convenient.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score
4.2Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 6.2.1
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 9 Apr 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

What to do

Upgrade nearform fast-jwt to 6.2.1.

Affected software

ProductAffectedFixed in
nearformfast-jwtAffected
  • >=5.0.0 <6.2.1
Fixed in
  • 6.2.1
npmfast-jwtpkg:npm/fast-jwtOther threatsAffected
  • <6.2.1 >=5.0.0
Fixed in
  • 6.2.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade fast-jwt to version 6.2.1 or later where this vulnerability is fixed. Since the vendor advisory indicates the issue is resolved in 6.2.1, applying this official fix is the recommended remediation. No alternative mitigations or workarounds are provided.

Description

fast-jwt provides fast JSON Web Token (JWT) implementation. From 5.0.0 to 6.2.0, a denial-of-service condition exists in fast-jwt when the allowedAud verification option is configured using a regular expression. Because the aud claim is attacker-controlled and the library evaluates it against the supplied RegExp, a crafted JWT can trigger catastrophic backtracking in the JavaScript regex engine, resulting in significant CPU consumption during verification. This vulnerability is fixed in 6.2.1.

References

Community reviews

Loading reviews…