ImpressCMS contains an authenticated remote code execution vulnerability in the custom tag module that allows authenticated administrators to… (CVE-2026-73679)
ImpressCMS has an authenticated remote code execution vulnerability in its custom tag module. Authenticated administrators can exploit this flaw by storing malicious PHP code in a custom tag with PHP type enabled. The vulnerability arises because the application decodes HTML-encoded content before passing it to an eval() function, bypassing HTML Purifier sanitization. This malicious payload executes on every frontend page load via the preload event system.
AI Analysis
Technical Summary
CVE-2026-73679 describes an authenticated remote code execution vulnerability in ImpressCMS's custom tag module. The flaw allows authenticated administrators to execute arbitrary PHP code by embedding a malicious payload in a custom tag configured with PHP type enabled. The application uses undoHtmlSpecialChars() to decode HTML-encoded content before passing it to the eval() function in renderWithPhp(), which bypasses HTML Purifier sanitization. The payload triggers on every frontend page load through the preload event system, enabling persistent code execution.
Potential Impact
Successful exploitation allows an authenticated administrator to execute arbitrary PHP code on the server, potentially leading to full system compromise, data theft, or service disruption. The vulnerability impacts confidentiality, integrity, and availability as indicated by the CVSS vector (C:H/I:H/A:H).
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict administrative access to trusted users only and monitor for suspicious activity related to custom tags with PHP type enabled.
ImpressCMS contains an authenticated remote code execution vulnerability in the custom tag module that allows authenticated administrators to… (CVE-2026-73679)
Description
ImpressCMS has an authenticated remote code execution vulnerability in its custom tag module. Authenticated administrators can exploit this flaw by storing malicious PHP code in a custom tag with PHP type enabled. The vulnerability arises because the application decodes HTML-encoded content before passing it to an eval() function, bypassing HTML Purifier sanitization. This malicious payload executes on every frontend page load via the preload event system.
CVSS v3.1
Score 7.2high
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-73679 describes an authenticated remote code execution vulnerability in ImpressCMS's custom tag module. The flaw allows authenticated administrators to execute arbitrary PHP code by embedding a malicious payload in a custom tag configured with PHP type enabled. The application uses undoHtmlSpecialChars() to decode HTML-encoded content before passing it to the eval() function in renderWithPhp(), which bypasses HTML Purifier sanitization. The payload triggers on every frontend page load through the preload event system, enabling persistent code execution.
Potential Impact
Successful exploitation allows an authenticated administrator to execute arbitrary PHP code on the server, potentially leading to full system compromise, data theft, or service disruption. The vulnerability impacts confidentiality, integrity, and availability as indicated by the CVSS vector (C:H/I:H/A:H).
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict administrative access to trusted users only and monitor for suspicious activity related to custom tags with PHP type enabled.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-j4fh-vmxm-5699
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-73679"]
- Ecosystems
- []
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6a7ff5f0bf8831d53987f0b9
Added to database: 08/15/2026, 05:15:28 UTC
Last enriched: 08/15/2026, 05:56:23 UTC
Last updated: 08/15/2026, 06:01:11 UTC
Views: 2
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.