CVE-2026-44351

Katalog CVE

CVSS 9.1 · Critical EPSS 0,33%

Kerentanan Improper Authentication. Skor CVSS 3.1 9.1 (Critical) menurut github.com.

Deskripsi (NVD)

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 empty string (''), for example via the common keys[decoded.header.kid] || '' JWKS-style fallback, fast-jwt converts it to a zero-length Buffer, hands it to crypto.createSecretKey, derives allowedAlgorithms = ['HS256','HS384','HS512'] from it, and then verifies the token's signature against an empty-key HMAC. The attacker simply computes HMAC-SHA256(key='', input='${header}.${payload}'), which Node accepts without complaint — and the verifier returns the attacker-chosen payload (sub, admin, scopes, etc.) as authentic. This vulnerability is fixed in 6.2.4.

Rincian

Terbit di NVD

13 Mei 2026

Terakhir diubah

17 Juni 2026

Status NVD

Deferred

CVSS 3.1

9.1 (Critical), sumber github.com
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N · uraikan di kalkulator

Jenis kelemahan (CWE)

CWE-287: Improper Authentication
CWE-326: Inadequate Encryption Strength
CWE-1391: Use of Weak Credentials

EPSS (30 hari)

0,33% peluang dieksploitasi; lebih tinggi dari 24,9% 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/nearform/fast-jwt/security/advisories/GHSA-gmvf-9v4p-v8jc