CVE-2026-109300EPSS p6.9%

CVE-2026-109300CVE-2026-109300

Description

Open WebUI from 0.6.31 before 0.11.4 contains a stored cross-site scripting vulnerability in its Markdown renderer, which treats user-authored tool-call details blocks as tool output and mounts their embeds attribute in script-enabled iframes. Authenticated users can post crafted channel messages, chat messages, or citation content that runs JavaScript in viewers' browsers, enabling in-app phishing, or session hijacking where iframeSandboxAllowSameOrigin is enabled.

Scoring

CVSS 4.6 ()
VectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
EPSS0.18% probability of exploitation · percentile 6.9% · 2026-10-17T12:00:28Z
Last modified2026-10-15
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.