September 25, 2026

CVE Watchtower

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CVE-2026-34950NVD

Vulnerability Summary

fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, the publicKeyPemMatcher regex in fast-jwt/src/crypto.js uses a ^ anchor that is defeated by any leading whitespace in the key string, re-enabling the exact same JWT algorithm confusion attack that CVE-2023-48223 patched.
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)
0.03%Probability
Root Weakness (CWE)
CWE-327: 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 < 6.2.0
Patched Versions
  • Nearform Fast-jwt 6.2.0
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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.
🚫Ad-Free — Uninterrupted experience.

External References