Riskcovery

CVE-2026-35039

fast-jwt Affected by Cache Confusion via cacheKeyBuilder Collisions Can Return Claims From a Different Token (Identity/Authorization Mixup)

State
Published
Severity
9.1 Critical
Published
Apr 6, 2026
Updated
May 13, 2026
Reserved
Mar 31, 2026

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.19.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NGitHub_M

Weaknesses

  • CWE-345 Insufficient Verification of Data Authenticity
  • CWE-706 Use of Incorrectly-Resolved Name or Reference
  • CWE-1289 Improper Validation of Unsafe Equivalence in Input

Affected Products

ProductVersions
fast-jwtnearform
  • >= 0.0.1, < 6.2.0Affected

References

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