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...

EUVD-2026-30560

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...

PT-2026-41315

Name of the Vulnerable Software and Affected Versions LibJWT versions 3.0.0 through 3.3.2 Description LibJWT accepts an RSA JSON Web Key JWK lacking an alg parameter as the verification key for HS256, HS384, or HS512 tokens. When using the OpenSSL backend, this results in HMAC verification...

Authentication Bypass

firebase/php-jwt is vulnerable to Authentication Bypass. The vulnerability is due to missing algorithm checks when calling the decode method allowing attackers bypass verification when using asymmetric keys RS256, RS384, RS512, ES256, ES384, ES512 when there is no algorithm specified within the...