What the vulnerability does
01Description
The PhastPress plugin for WordPress is vulnerable to Unauthenticated Arbitrary File Read via null byte injection in all versions up to, and including, 3.7. This is due to a discrepancy between the extension validation in `getExtensionForURL()` which operates on URL-decoded paths, and `appendNormalized()` which strips everything after a null byte before constructing the filesystem path. This makes it possible for unauthenticated attackers to read arbitrary files from the webroot, including wp-config.php, by appending a double URL-encoded null byte (%2500) followed by an allowed extension (.txt) to the file path.
Explanation of Vulnerability in Simple Terms
02Summary
PhastPress versions 3.7 and earlier contain a vulnerability that allows unauthenticated attackers to read sensitive data, modify site content, or disrupt service without any user interaction. The vulnerability stems from improper input handling. All sites running affected versions should update immediately to version 3.10 or later.
What an attacker can do
03Attacker Capabilities
Read sensitive data, modify site content, or disrupt service without authentication.
Potential impact on your site
04Site Impact
Attackers can compromise your site's data, content, and availability without needing a user account.
Conditions required to exploit
05Prerequisites
Network access only; no authentication or user interaction required.
Key dates
06Disclosure timeline
December 23, 2025
CVE published
April 8, 2026
Record updated
