CVE-2026-24906

A stored cross-site scripting (XSS) vulnerability was identified in the Backend Editor Settings. The Markup Classes fields (used for paragraph styles, inline styles, table styles, etc.) did not sanitize input to valid CSS class name characters. Malicious values were rendered unsanitized in Froala editor dropdown menus, allowing JavaScript execution when any user opened a RichEditor.

Workarounds

If upgrading immediately is not possible:

• Restrict editor settings permissions to fully trusted administrators only

References

• Reported by Chris Alupului

• Stored XSS via editor settings rendered in RichEditor dropdowns
• Could allow privilege escalation if a superuser opens any RichEditor (e.g., editing a blog post)
• Requires authenticated backend access with editor settings permissions
• Triggers on routine content editing operations

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

CVE-2026-24906 has a CVSS score of 5.4 (Medium). The vector is network-reachable, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.1.10, 3.7.14); upgrading removes the vulnerable code path.

Kodem intelligence

The vulnerability has been patched in v3.7.14 and v4.1.10. All users are encouraged to upgrade to the latest patched version.

1. What is CVE-2026-24906? CVE-2026-24906 is a medium-severity cross-site scripting (XSS) vulnerability in october/system (composer), affecting versions >= 4.0.0, <= 4.1.9. It is fixed in 4.1.10, 3.7.14. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is CVE-2026-24906? CVE-2026-24906 has a CVSS score of 5.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of october/system are affected by CVE-2026-24906? october/system (composer) versions >= 4.0.0, <= 4.1.9 is affected.
4. Is there a fix for CVE-2026-24906? Yes. CVE-2026-24906 is fixed in 4.1.10, 3.7.14. Upgrade to this version or later.
5. Is CVE-2026-24906 exploitable, and should I be worried? Whether CVE-2026-24906 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-24906 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-24906?
   • Upgrade october/system to 4.1.10 or later
   • Upgrade october/system to 3.7.14 or later