{"id":"CVE-2026-27937","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-27937","summary":"October CMS: Reflected XSS via DataTable Form Widget","details":"A reflected Cross-Site Scripting (XSS) vulnerability was identified in the backend DataTable widget where a query parameter was rendered without proper output escaping.\n\n### Impact\n- Reflected XSS only, no stored/persistent component\n- The backend URL prefix is customizable and must be known or guessed by the attacker\n- Requires an authenticated backend user to visit a crafted URL\n- No direct access is gained without social engineering\n\n### Patches\nThe vulnerability has been patched in v3.7.16 and v4.1.16. The affected parameter is now properly escaped. All users are encouraged to upgrade to the latest patched version.\n\n### Workarounds\n- Use a non-default backend URL prefix (recommended as standard practice)\n- Implement a Content Security Policy (CSP) for backend pages","published":"2026-04-21T17:15:21Z","modified":"2026-05-05T16:07:59.629264Z","cvss":{"score":3.1,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N"},"epss":{"score":0.00144,"percentile":0.04041,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"october/system","fixedVersion":"3.7.16"},{"ecosystem":"Packagist","name":"october/system","fixedVersion":null}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/octobercms/october/security/advisories/GHSA-jj38-h5w5-mvpf"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27937"},{"type":"PACKAGE","url":"https://github.com/octobercms/october"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-05-05T16:07:59.629264Z"}}