Detections
Analytics

SCA: security update for fast-jwt (GHSA-gmvf-9v4p-v8jc)

critical Tenable Cloud Security Plugin ID 441303

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - 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. (CVE-2026-44351)

Solution

Update the fast-jwt library and its related packages to version 6.2.4 or later.

See Also

https://github.com/advisories/GHSA-gmvf-9v4p-v8jc

Plugin Details

Severity: Critical

ID: 441303

Version: Revision 1.7

Type: Local

Family: SCA Checks

Published: 5/7/2026

Updated: 7/2/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Medium

Score: 4.3

Percentile: 53.64

Vendor

Vendor Severity: Critical

CVSS v2

Risk Factor: High

Base Score: 9.4

Temporal Score: 7

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N

CVSS Score Source: CVE-2026-44351

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 5/6/2026

Vulnerability Publication Date: 5/6/2026

Reference Information

CVE: CVE-2026-44351