Vulnerability in WordPress Faust.js (CVE-2026-54239)
Summary
Vulnerability in WordPress Faust.js (CVE-2026-54239). Successful exploitation can lead to full system takeover. Exploitable via GET /generate.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-54239 has been found in WordPress Faust.js.
Attackers can target a specific entry point like GET /generate over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "WordPress Faust.js CVE-2026-54239" on the vendor's site.
CVE-2026-54239 (WordPress Faust.js) — CWE-345 / CVSS v3 8.8
Attack vector: remote (network-reachable) / no user interaction
Attack surface: GET /generate
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-345) exists in WordPress Faust.js. Attackers reach the vulnerable code path via GET /generate.
Check the vendor advisory for the affected versions of WordPress Faust.js. Attack surface: GET /generate.
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual GET /generate requests with malformed payloads or SQL meta-characters. Run grep -r 'Faust.js' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Faust.js' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Faust.jsを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'GET /generate' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /generateへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Post-deployment verification verify
Replay attack against GET /generate on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。