Answer in brief
CVE-2026-107724 records a High severity (CVSS 7.4) vulnerability in fast-jwt treats raw public JWK JSON as an HMAC secret, enabling HS256 token forgery. The current sources do not mark it as known exploited. The current feed maps nearform/fast-jwt (generic), fast-jwt (npm), fast-jwt (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps nearform/fast-jwt (generic), fast-jwt (npm), fast-jwt (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| nearform/fast-jwtgeneric | >=6.2.4 <6.3.0 | 6.3.0 |
| fast-jwtnpm | =6.2.4 | 6.3.0 |
| fast-jwtnpm | >=6.2.4 <6.3.0 | 6.3.0 |
Published upstream
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 8, 2026
fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.2.4, fast-jwt can classify raw serialized public JWK or JWKS JSON as an HMAC secret because src/crypto.js performDetectPublicKeyAlgorithms treats non-PEM strings as symmetric key material. If HS256 is explicitly allowed or inferred, an attacker who knows the exact serialized public-key bytes can use those bytes as an HMAC key and create a token containing arbitrary claims that createVerifier accepts. Serialization ordering or whitespace differences can prevent exploitation, and applications using supported PEM keys with an asymmetric-only algorithm allowlist are not affected. This issue is fixed in version 6.3.0.
Quoted source text, attributed separately from HOL analysis.