CVE-2026-16889

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.

References

https://openequella.github.io/guides/

https://github.com/openequella/openEQUELLA/security/advisories/GHSA-q2xv-rffq-mj5w

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-112563

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4

EPSS