CVE-2026-34240 in appsup-dart jose

Sumário (Inglês)

JOSE is a Javascript Object Signing and Encryption (JOSE) library. Prior to version 0.3.5+1, a vulnerability in jose could allow an unauthenticated, remote attacker to forge valid JWS/JWT tokens by using a key embedded in the JOSE header (jwk). The vulnerability exists because key selection could treat header-provided jwk as a verification candidate even when that key was not present in the trusted key store. Since JOSE headers are untrusted input, an attacker could exploit this by creating a token payload, embedding an attacker-controlled public key in the header, and signing with the matching private key. Applications using affected versions for token verification are impacted. This issue has been patched in version 0.3.5+1. A workaround for this issue involves rejecting tokens where header jwk is present unless that jwk matches a key already present in the application's trusted key store.

Responsável

GitHub_M

Reservar

26/03/2026

Divulgação

31/03/2026

Inscrições

VulDB provides additional information and datapoints for this CVE:

ID	Vulnerabilidade	CWE	Exp	Con	CVE
354436	appsup-dart jose JWS/JWT Autenticação fraca	347	Não definido	Correção oficial	CVE-2026-34240