{"id":"CVE-2025-61676","aliases":["GHSA-wvpq-h33f-8rp6"],"url":"https://o3.security/vulnerability/CVE-2025-61676","summary":"October CMS Vulnerable to Stored XSS via Branding Styles","details":"A cross-site scripting (XSS) vulnerabilities was identified in October CMS backend configuration forms:\n\n- **Branding and Appearances Styles**  \n   A user with the `Customize Backend Styles` permission could inject malicious HTML/JS into the stylesheet input at  \n   *Settings → Branding & Appearance → Styles*.  \n\nA specially crafted input could break out of the intended `<style>` context, allowing arbitrary script execution across backend pages for all users.\n\n---\n\n### Impact\n- Persistent XSS across the backend interface.  \n- Exploitable by lower-privileged accounts with the above permissions.  \n- Potential consequences include privilege escalation, session hijacking, and execution of unauthorized actions in victim sessions.\n\n---\n\n### Patches\nThe vulnerability has been patched in **v4.0.12** and **v3.7.13**.  \nStylesheet inputs are now sanitized to prevent injection of arbitrary HTML/JS.  \n\nAll users are strongly encouraged to upgrade to the latest patched version.\n\n---\n\n### Workarounds\nIf upgrading immediately is not possible:  \n- Restrict the permissions `Customize Backend Styles` to fully trusted administrators only.  \n\nThis reduces exposure but does not fully eliminate risk.\n\n---\n\n### Credits\n- Reported by **[Nakkouch Tarek](https://github.com/nakkouchtarek)**","published":"2026-01-10T03:14:00.708Z","modified":"2026-08-12T03:51:47.400536685Z","cvss":{"score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N"},"epss":{"score":0.00276,"percentile":0.20071,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"october/system","fixedVersion":"3.7.13"},{"ecosystem":"Packagist","name":"october/system","fixedVersion":"4.0.12"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/61xxx/CVE-2025-61676.json"},{"type":"ADVISORY","url":"https://github.com/octobercms/october/security/advisories/GHSA-wvpq-h33f-8rp6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-61676"},{"type":"PACKAGE","url":"https://github.com/octobercms/october"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:47.400536685Z"}}