CVE-2026-35039
CRITICALfast-jwt Affected by Cache Confusion via cacheKeyBuilder Collisions Can Return Claims From a Different Token (Identity/Authorization Mixup)
Title source: cnaDescription
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.
References (2)
Core 2
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/nearform/fast-jwt/security/advisories/GHSA-rp9m-7r4c-75qg
X_Refsource_Misc x_refsource_misc
https://github.com/nearform/fast-jwt/commit/de121056c6415b58770c60640881eaec67ac4ceb
Scores
CVSS v3
9.1
EPSS
0.0021
EPSS Percentile
11.4%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
total
Details
CWE
CWE-1289
CWE-345
CWE-706
Status
published
Products (4)
nearform/fast-jwt
0.1.0 - 6.1.0
nearform/fast-jwt
>= 0.0.1, < 6.1.0
nearform/fast-jwt
>= 0.0.1, < 6.2.0
npm/fast-jwt
0.0.1 - 6.1.0npm
Published
Apr 06, 2026
Tracked Since
Apr 06, 2026