Use of a Broken or Risky Cryptographic Algorithm Affecting fast-jwt package, versions *
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Start learning- Snyk IDSNYK-JS-FASTJWT-15876721
- published3 Apr 2026
- disclosed2 Apr 2026
- creditRitvik Arya
Introduced: 2 Apr 2026
NewCVE-2026-34950 (opens in a new tab)How to fix?
There is no fixed version for fast-jwt.
Overview
fast-jwt is a Fast JSON Web Token implementation
Affected versions of this package are vulnerable to Use of a Broken or Risky Cryptographic Algorithm in the performDetectPublicKeyAlgorithms function due to improper handling of leading whitespace in PEM key strings. An attacker can gain unauthorized access and forge tokens by supplying a public key with leading whitespace, causing the key to be misclassified and allowing arbitrary payloads to be accepted as valid.
Note:
This vulnerability is caused by an incomplete fix for CVE-2023-48223.