Improper Verification of Cryptographic Signature Affecting web-token/jwt-experimental package, versions <3.4.10>=4.0.0, <4.0.7>=4.1.0, <4.1.7
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- published23 Jun 2026
- disclosed17 Jun 2026
- creditUnknown
Introduced: 17 Jun 2026
CVE NOT AVAILABLE CWE-347 (opens in a new tab)How to fix?
Upgrade web-token/jwt-experimental to version 3.4.10, 4.0.7, 4.1.7 or higher.
Overview
Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature via missing authentication tag verification in the experimental Chacha20Poly1305 key-encryption algorithm. An attacker can modify an encrypted content-encryption key (CEK) in transit without detection because the Poly1305 authentication tag generated during encryption is discarded and never verified during decryption. As a result, the intended AEAD construction is reduced to unauthenticated ChaCha20, allowing tampering with the wrapped key while bypassing integrity protection.
Note: This is only exploitable if the application registers Jose\Experimental\KeyEncryption\Chacha20Poly1305 (web-token/jwt-experimental) as a JWE key-encryption algorithm.