CVE-2026-73679

Description

ImpressCMS contains an authenticated remote code execution vulnerability in the custom tag module that allows authenticated administrators to execute arbitrary PHP code by storing a malicious payload in a custom tag with PHP type enabled. The application decodes HTML-encoded content via undoHtmlSpecialChars() before passing it to eval() in the renderWithPhp() method, bypassing HTML Purifier sanitization, and the payload is triggered on every frontend page load through the preload event system.

References

https://www.vulncheck.com/advisories/impresscms-authenticated-rce-via-php-custom-tag-eval

https://github.com/ImpressCMS/impresscms

https://github.com/DevVaibhav07/VULN-POC/blob/main/ImpressCMSRCCE.md

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4