Collected research

MyBB Admin Panel RCE CVE-2023-41362

MyBB's admin panel rejects templates containing executable PHP syntax, but the check runs a preg_replace first and never inspects its return value. A template padded with thousands of array-index repetitions blows the PCRE backtrack limit, so preg_replace returns an empty string, the check passes, and the saved template's payload is executed by MyBB's eval-based renderer. CVE-2023-41362.

Record

Published by

blog.sorcery.ie

Topic

Server

In the archive

• Collected in the 2023 research round

Related sources

• Patch and advisory released Advisory
• Proof of concept

Tags

• ssti
• filter-bypass
• algorithmic-complexity
• rce
• php
• cve
• owasp-a03-2021
• owasp-a04-2021
• owasp-a05-2021

This page is the archive's own catalogue record. The research is the work of blog.sorcery.ie, first published at the original source. Preserved copies are kept so the citation survives its host; this one was last captured on 10 August 2026.