Stored XSS via Pre-Login Notice Image Upload Serves Attacker HTML from Application Origin (Apereo Foundation openEQUELLA)

CVE-2026-16889
MEDIUM 4.8

At a glance

Source
NVD
EPSS
EPSS 0.32 % · percentile 24 ()
State
PUBLISHED
Published
Updated
Assigner
MON-CSIRT
NVD status
Deferred

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.

Weaknesses (CWE)

  • CWE-434 — Unrestricted Upload of File with Dangerous Type

References

Scores

VersionScoreVectorScored by
CVSS 4.0MEDIUM 4.8CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:NMON-CSIRT
CVSS 4.0MEDIUM 4.8CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XNVD · 9c1820ae-fb77-4810-a8aa-ca46e7474d2f (Secondary)

European references

Affected products

ProductVersions
Apereo Foundation · openEQUELLAaffected 2019.1 < 2026.1

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD