September 25, 2026

CVE Watchtower

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CVE-2026-35039NVD

Vulnerability Summary

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.
Severity Level
CRITICAL(9.1)
Published Date
Apr 6, 2026
Last Modified
Apr 22, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
0.02%Probability
Root Weakness (CWE)
CWE-345: Unknown/Unlisted Weakness ↗
Refer to the official MITRE database for detailed architectural specifications regarding this weakness.
CWE-706: Unknown/Unlisted Weakness ↗
Refer to the official MITRE database for detailed architectural specifications regarding this weakness.
CWE-1289: Unknown/Unlisted Weakness ↗
Refer to the official MITRE database for detailed architectural specifications regarding this weakness.
CVSS v3.1 Base Metrics — Score 9.1 (CRITICAL)
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityNone

Affected & Patched Versions

Affected Versions
  • Nearform Fast-jwt >= 0.1.0 and < 6.1.0
Patched Versions
  • Nearform Fast-jwt 6.1.0
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📧Email Delivery — Threat intel straight to your inbox.
♾️Unlimited Vendors — Track your entire stack.
🚨All New CVEs — Be the first to know.
⚙️Custom EPSS — Filter noise, focus on risk.
💬Webhooks — Slack & Teams integration.
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External References