All vulnerabilities
CVE-2026-16889GHSA-q2xv-rffq-mj5w

openEQUELLA: Stored XSS via Pre-Login Notice Image Upload Serves Attacker HTML from Application Origin

Apereo Foundation openEQUELLA
Open in ThreatlineRecord JSON
CVSS
4.8Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)No scoreNo FIRST EPSS score in this snapshot yet
Fixed in2026.1Fixed versionCVE List
Published29 Oct 2026Updated 29 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

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.

Text from CVE List

Affected versions 1

  • openEQUELLAaffected: 2019.1 before 2026.1CVE List

References 2