RCE in Impresscms
CVE-2026-73679
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.
Vulnerability class: RCE (Remote Code Execution)
CVSS v3 metric
CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Impresscms — versions 0
Weakness classification (CWE)
References
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-73679?
- CVE-2026-73679 is a high-severity vulnerability in Impresscms, classified under Code Injection. CVSS score: 7.2/10. Published 2026-08-14.
- How severe is CVE-2026-73679?
- High severity. CVSS v3 base score is 7.2 out of 10.