CVE-2026-44699

Katalog CVE

CVSS 9.1 · Critical EPSS 0,35%

Kerentanan Use of a Broken or Risky Cryptographic Algorithm. Skor CVSS 4.0 9.1 (Critical) menurut github.com.

Deskripsi (NVD)

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.

Rincian

Terbit di NVD

15 Mei 2026

Terakhir diubah

17 Juni 2026

Status NVD

Deferred

CVSS 4.0

9.1 (Critical), sumber github.com
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X · uraikan di kalkulator

Jenis kelemahan (CWE)

CWE-327: Use of a Broken or Risky Cryptographic Algorithm
CWE-347: Improper Verification of Cryptographic Signature

EPSS (30 hari)

0,35% peluang dieksploitasi; lebih tinggi dari 26,9% CVE lain

Produk dan versi terdampak

NVD belum mencantumkan data produk (CPE) untuk CVE ini. Produk yang terdampak biasanya disebut di deskripsi dan di advisory vendor pada daftar referensi.

Referensi dan perbaikan

• https://github.com/benmcollins/libjwt/security/advisories/GHSA-q843-6q5f-w55g