CVE-2026-109300: medium-severity vulnerability in open-webui
Open WebUI 0.6.31 before 0.11.4 Stored XSS via Tool-Call Embeds
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.1epss 0.2%
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Affected products
open-webui · open-webuiRelated CVEs — open-webui
In the same product, most dangerous first.
CVE-2025-64496HIGHOpen WebUI Affected by an External Model Server (Direct Connections) Code Injection via SSE EventsEPSS 7.2%CVE-2026-34222HIGHOpen WebUI has Broken Access Control in Tool ValvesEPSS 5.1%CVE-2025-65958HIGHOpen WebUI vulnerable to Server-Side Request Forgery (SSRF) via Arbitrary URL Processing in /api/v1/retrieval/process/webEPSS 4.4%CVE-2026-28788HIGHOpen WebUI's process_files_batch() endpoint missing ownership check, allows unauthorized file overwriteEPSS 3.0%CVE-2026-44551CRITICALOpen WebUI: LDAP Empty Password Authentication BypassEPSS 1.5%CVE-2026-45397MEDIUMOpen WebUI: Unauthenticated RAG Configuration DisclosureEPSS 0.8%