CVE-2026-35039

critical · 9.1

fast-jwt provides fast JSON Web Token (JWT) implementation. From 0.0.1 to before 6.2.0, setting up a custom cacheKeyBuilder method which does not properly create unique keys for different tokens can lead to cache collisions. This could cause tokens to be mis-identified during the verification process leading to valid tokens returning claims from different valid tokens and users being mis-identified as other users based on the wrong token. Version 6.2.0 contains a patch.

9.1

CVSS

0.2%

EPSS (exploit prob.)

12th

EPSS percentile

2026-04-06

Published

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Weaknesses

CWE-345CWE-706CWE-1289

Affected products

Vendor	Product	Affected versions
nearform	fast-jwt	>= 0.1.0, < 6.1.0

Check a specific version with /api/v1/cve/match.

References

https://github.com/nearform/fast-jwt/commit/de121056c6415b58770c60640881eaec67ac4ceb
https://github.com/nearform/fast-jwt/security/advisories/GHSA-rp9m-7r4c-75qg

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-35039