CVE-2026-107722

fast-jwt provides fast JSON Web Token (JWT) implementation. From 6.2.0 until 6.3.0, fast-jwt can misclassify RSA public-key text as an HMAC secret when the key has non-whitespace content before its PEM header. In src/crypto.js, performDetectPublicKeyAlgorithms trims whitespace but publicKeyPemMatcher remains start-anchored, so comments, control characters, zero-width characters, or wrapper text can prevent PEM detection and reach the HMAC fallback. An attacker who knows the public key bytes can sign arbitrary HS256 claims with that public material when HS256 is inferred or allowed, resulting in authentication or authorization bypass. An asymmetric-only algorithm allowlist prevents the attack. This issue is fixed in version 6.3.0.
Configurations

No configuration.

History

13 Oct 2026, 17:17

Type Values Removed Values Added
References () https://github.com/nearform/fast-jwt/security/advisories/GHSA-ww5h-9m49-7xx4 - () https://github.com/nearform/fast-jwt/security/advisories/GHSA-ww5h-9m49-7xx4 -

08 Oct 2026, 22:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-10-08 22:17

Updated : 2026-10-13 17:17


NVD link : CVE-2026-107722

Mitre link : CVE-2026-107722

CVE.ORG link : CVE-2026-107722


JSON object : View

Products Affected

No product.

CWE
CWE-347

Improper Verification of Cryptographic Signature