CVE-2026-7886
Concrete CMS 9.5.0 and below is vulnerable to IDOR in AddMessage/UpdateMessage via attachments[] parameter which can lead to file permission bypass. The `AddMessage` and `UpdateMessage` conversation controllers accept user-supplied file attachment IDs and load files directly via `$em->find(File::class, $attachmentID)` without checking per-file permissions (`canViewFile()`). A user who can post in any conversation can reference any file in the CMS file manager by its sequential ID, effectively bypassing the file permission system. The Concrete CMS security team gave this vulnerability a
Exploitation Probability (EPSS)
Low PriorityThe Exploit Prediction Scoring System (EPSS) uses machine learning to estimate the probability that a vulnerability will be exploited in the wild within the next 30 days.
7-Day Exploitation Trend
Vulnerability Timeline
1 eventsThreat Actor Attribution
PREMIUM INTELRemediation & Mitigation
SOLUTIONOfficial patches and mitigation steps are available for this vulnerability.
apt-get update && apt-get upgrade -y specific-package
# Verify installation
dpkg -l | grep package-name
Am I Vulnerable?
Check your domain or package.json for CVE-2026-7886 exposure.
Vulnerability Details
Need Manual Validation?
Automated scanners flag false positives. Get a manual pentest validation for this CVE.