CVE-2025-61676 October CMS Vulnerable to Stored XSS via Branding Styles
Attackers with backend style permissions can inject malicious scripts into branding settings, leading to arbitrary code execution for all backend users.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2025-61676?
CVE-2025-61676 is a medium-severity cross-site scripting vulnerability in Octobercms October, published on 10 Jan 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
October is a Content Management System (CMS) and web platform. Prior to versions 3.7.13 and 4.0.12, a cross-site scripting (XSS) vulnerabilities was identified in October CMS backend configuration forms. A user with the Customize Backend Styles permission could inject malicious HTML/JS into the stylesheet input at Styles from Branding & Appearance settings. A specially crafted input could break out of the intended <style> context, allowing arbitrary script execution across backend pages for all users. This issue has been patched in versions 3.7.13 and 4.0.12.
Weakness: CWE-79
Which versions are affected by CVE-2025-61676?
4 open source packages ship an affected version, including october/system. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
october/system Packagist | All versions | 3.7.13 |
october/system Packagist | All versions | 3.7.13 |
october/system Packagist | From 4.0.0 | 4.0.12 |
october/system Packagist | From 4.0.0 | 4.0.12 |
Products include Octobercms October.
How do I fix CVE-2025-61676?
Upgrade october/system to a fixed version for your release line: 3.7.13 or 4.0.12.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2025-61676 being exploited?
There is no known exploitation of CVE-2025-61676 in the wild and no public exploit code.
Other vulnerabilities in Octobercms October
Sources
Also known as GHSA-wvpq-h33f-8rp6.