CVE-2026-45318

MEDIUM

Open WebUI: Stored XSS via unsanitized Office/Excel/DOCX file preview rendering ({@html} without DOMPurify)

Title source: cna
STIX 2.1

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.3, his advisory tracks a regression of the original Excel-preview XSS (CVE-2026-44549). The same root cause — XLSX.utils.sheet_to_html() output rendered via {@html excelHtml} without DOMPurify — was reintroduced sometime after v0.8.0 and is exploitable again This vulnerability is fixed in 0.9.3.

References (1)

Core 1
Core References

Scores

CVSS v3 5.4
EPSS 0.0001
EPSS Percentile 1.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-79
Status published
Products (3)
open-webui/open-webui < 0.9.3
openwebui/open_webui < 0.9.3
pypi/open-webui 0 - 0.9.3PyPI
Published May 15, 2026
Tracked Since May 16, 2026