CVE-2026-44699: benmcollins libjwt, слаба криптография

Описание

Оригинално описание

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 JWT without knowing any secret or RSA private key. This is an algorithm-confusion authentication bypass. It affects applications that load RSA keys from JWKS where alg is omitted, which is valid JWK syntax and common in real deployments, and then choose the verification algorithm from the JWT header, for example in a kid lookup callback. This vulnerability is fixed in 3.3.3.

Засегнати продукти

• benmcollins libjwt: >= 3.0.0, < 3.3.3

Вид слабост

• CWE-327 Използване на компрометиран или рисков криптографски алгоритъм
• CWE-347 Неправилна проверка на криптографски подпис

История

Други уязвимости в benmcollins libjwt

• 5.8CVE-2026-33996

Първоизточници

• https://www.cve.org/CVERecord?id=CVE-2026-44699
• https://nvd.nist.gov/vuln/detail/CVE-2026-44699
• https://github.com/benmcollins/libjwt/security/advisories/GHSA-q843-6q5f-w55g