AEGLIX vulnerability intelligence
CVE-2026-44351
CRITICAL · CVSS 9.1 · Deferred
Published: 2026-05-13 · Updated: 2026-10-26 · Source: NVD
Stored catalog record
Source record retrieved 2026-10-28T10:25:00.584405+00:00. Scheduled imports handle updates; this page does not assert that the provider was queried just now.
Vulnerability overview
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.
Patch review priority
Critical technical severity
- CVSS is at least 9.0; exploitation is not established by severity alone.
FIRST EPSS: 0.25% · percentile 16.3 · score date 2026-10-27.
EPSS estimates probability of exploitation in the next 30 days. It does not measure your exposure or prove exploitation. The elevated threshold is 10%; CISA KEV takes precedence. About FIRST EPSS ↗
Severity and scoring
- CVSS score
- 9.1 · CRITICAL
- CVSS version
- 3.1
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- Weaknesses
- CWE-1391, CWE-287, CWE-326
CVSS measures technical severity; it does not establish whether this vulnerability is being exploited in your environment.
Known exploitation and remediation
Not listed in the CISA catalog retrieved for this record. This does not establish that exploitation has not occurred.
Verify affected versions and patch availability in the vendor advisory before making changes.
Affected products and versions
NVD has not supplied affected-version configurations for this record. Check the vendor references below.