CVE Catalog

CVE-2026-54239

HighCVSS 8.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.32%

23th percentile - higher than 23% of all known CVEs

Summary

In the FaustWP WordPress plugin prior to 1.8.11, only the ciphertext in the token envelope is authenticated, and the 16-byte initialization vector is excluded from the HMAC. 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 yield an Administrator access token and permit full WordPress REST API access, administrator-account creation, plugin installation, and arbitrary code execution. The issue is fixed in 1.8.11.

Risk Assessment

An attacker with logged-in user privileges can escalate to administrator and take full control of the WordPress site, including arbitrary code execution. This can lead to complete compromise of the site and its data.

Recommendation

Update the FaustWP plugin to version 1.8.11 or later. Until patched, restrict the ability of low-privileged users to obtain authorization codes.

Related vulnerabilities

Original NVD description (English 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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS