CVE-2026-24906 Octobercms CVE debrief

Who should care

Administrators and users with access to the Backend Editor Settings of October CMS should assess their exposure and take necessary actions to prevent exploitation. This includes reviewing user access, updating to fixed versions, and restricting permissions to trusted administrators. Additionally, security teams and vulnerability management teams should be aware of the potential impact and take steps to mitigate it.

Why it matters

A Stored Cross-Site Scripting (XSS) vulnerability in October CMS can lead to privilege escalation and JavaScript execution, requiring attention from administrators and users with access to Backend Editor Settings.

• Privilege escalation is possible if a superuser opens any RichEditor during routine content editing
• JavaScript execution can occur when any user opens a RichEditor
• Exploitation requires authenticated backend access with editor settings permissions

Technical summary

The vulnerability exists in the Backend Editor Settings of October CMS, specifically in the Markup Classes fields. Malicious input was not properly sanitized, allowing JavaScript execution when a user opened a RichEditor. Exploitation requires authenticated backend access with editor settings permissions. This issue has been fixed in versions 3.7.14 and 4.1.10. To prevent exploitation, it is recommended to update to these versions or restrict editor settings permissions to fully trusted administrators only. The vulnerability can lead to privilege escalation and JavaScript execution.

Defensive priority

Medium priority should be given to updating October CMS to versions 3.7.14 or 4.1.10, or applying the workaround by restricting editor settings permissions to fully trusted administrators only.

Recommended defensive actions

• Update October CMS to version 3.7.14 or 4.1.10
• Restrict editor settings permissions to fully trusted administrators only
• Review and monitor user access to Backend Editor Settings
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record and NVD vulnerability detail provide information on the vulnerability, its impact, and the fixed versions. A vendor advisory is also available. To verify and assess exposure, defenders should review the official CVE Program record and NIST NVD detail page. They should also check for any additional information from the vendor advisory. Exploitation requires authenticated backend access with editor settings permissions, which implies that users with such access should be cautious. The Markup Classes fields did not sanitiz

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.