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...

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...

CVE-2026-44351

fast-jwt provides fast JSON Web Token JWT implementation. Prior to 6.2.4, a critical authentication-bypass vulnerability in fast-jwt's async key-resolver flow allows any unauthenticated attacker to forge arbitrary JWTs that are accepted as authentic. When the application's key resolver returns an...