{"id":"CVE-2026-16889","published":"2026-10-29T02:16:51.803","lastModified":"2026-10-29T04:18:35.640","description":"In openEQUELLA before 2026.1, the pre-login notice image upload endpoint (PUT /api/preloginnotice/image/{name}) does not validate the type of uploaded files and serves them with a Content-Type derived from the supplied filename. A user holding the EDIT_SYSTEM_SETTINGS permission can upload an HTML file that is then served as text/html from the openEQUELLA origin, resulting in stored cross-site scripting. Unauthenticated exploitation is possible where EDIT_SYSTEM_SETTINGS has been granted to the guest user or everyone.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":["CWE-434"],"vendors":[],"products":[],"references":[{"url":"https://github.com/openequella/openEQUELLA/security/advisories/GHSA-q2xv-rffq-mj5w","tags":[]},{"url":"https://openequella.github.io/guides/","tags":[]}],"exploitRefs":[{"url":"https://github.com/openequella/openEQUELLA/security/advisories/GHSA-q2xv-rffq-mj5w","tags":[]}],"hasPoc":true,"ai":null}