CVEvulnerability

CVE-2026-54239

8.8 HIGH Published 2026-09-17 Modified 2026-09-24 Official page ↗
Status
Awaiting Analysis
Published
2026-09-17
Last modified
2026-09-24
Assigner
[email protected]
CVSS 3.1 ([email protected])
8.8 HIGH — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weaknesses
CWE-345, CWE-639

Description

Faust.js is a headless WordPress toolkit. Prior to 1.8.11, the FaustWP WordPress plugin authenticates only the ciphertext in its token envelope and excludes the 16-byte initialization vector from the HMAC in WPE\FaustWP\Auth\encrypt() and WPE\FaustWP\Auth\decrypt() in plugins/faustwp/includes/auth/functions.php. A logged-in non-administrator who obtains an authorization code from GET /generate can modify the unauthenticated initialization vector so that CBC decryption changes the token type and user identifier while the HMAC remains valid. This can produce an access token for an Administrator and permit full WordPress REST API access, administrator-account creation, plugin installation, and arbitrary code execution. This issue is fixed in repository version 1.8.11.

Related

Weakness · CWE (2)

  • CWE-345 Insufficient Verification of Data Authenticity weakness
  • CWE-639 Authorization Bypass Through User-Controlled Key weakness

References