XSS2Shell

WordPress Patches High-Severity XSS2Shell Flaw Enabling Remote Code Execution (CVE-2026-64638)

WordPress has released a fix for a high-severity vulnerability in its core that can turn a malicious login attempt into remote PHP code execution on the server. The flaw, tracked as CVE-2026-64638 and rated 8.9 on CVSS, is named XSS2Shell and begins as a reflected cross-site scripting issue on the authentication screen. An unauthenticated attacker can submit a specially crafted username that bypasses sanitization mechanisms due to differences in how PHP and WordPress interpret certain characters, allowing controlled HTML elements to be injected into the login page. This leads to JavaScript execution in the site domain, and when an authenticated administrator visits a prepared page, the attacker can abuse the existing session to authorize application credentials and upload arbitrary PHP code. The patch is included in WordPress 7.0.3 released on August 6, with backports available for branches as old as 4.7. No public exploitation has been confirmed yet, but the technical details make immediate updating a priority for site administrators.