CVE-2025-61676: October CMS Vulnerable to Stored XSS via Branding Styles

January 9, 2026 (updated January 11, 2026)

A cross-site scripting (XSS) vulnerabilities was identified in October CMS backend configuration forms:

Branding and Appearances Styles A user with the Customize Backend Styles permission could inject malicious HTML/JS into the stylesheet input at Settings → Branding & Appearance → Styles.

A specially crafted input could break out of the intended <style> context, allowing arbitrary script execution across backend pages for all users.

References

github.com/advisories/GHSA-wvpq-h33f-8rp6
github.com/octobercms/october
github.com/octobercms/october/security/advisories/GHSA-wvpq-h33f-8rp6
nvd.nist.gov/vuln/detail/CVE-2025-61676

Code Behaviors & Features

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