CVE-2026-44699

LibJWT is a C JSON Web Token Library. From 3.0.0 to 3.3.2, libjwt accepts an RSA JWK that does not contain an alg parameter as the verification key for an HS256/HS384/HS512 token. In the OpenSSL backend, this causes HMAC verification to run with a zero-length key, so an attacker can forge a valid...

CVE-2026-44699 LibJWT: Algorithm confusion allows JWT forgery with RSA JWK as empty-key HMAC

LibJWT is a C JSON Web Token Library. From 3.0.0 to 3.3.2, libjwt accepts an RSA JWK that does not contain an alg parameter as the verification key for an HS256/HS384/HS512 token. In the OpenSSL backend, this causes HMAC verification to run with a zero-length key, so an attacker can forge a valid...

CVE-2026-44699

LibJWT (C JSON Web Token library) versions 3.0.0–3.3.2 are vulnerable when an RSA JWK without an alg parameter is used as the verification key for HS256/HS384/HS512. In the OpenSSL backend, this can cause HMAC verification to run with a zero-length key, enabling an attacker to forge a valid JWT w...