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.
Published: 2026-10-12
Score: 5.1 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

No analysis available yet.

Remediation

No remediation available yet.

Tracking

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Advisories

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History

Mon, 12 Oct 2026 16:30:00 +0000

Type Values Removed Values Added
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.
Title Open WebUI 0.6.31 before 0.11.4 Stored XSS via Tool-Call Embeds
First Time appeared Openwebui
Openwebui open Webui
Weaknesses CWE-79
CPEs cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*
Vendors & Products Openwebui
Openwebui open Webui
References
Metrics cvssV3_1

{'score': 4.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.1, 'vector': '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'}

Subscriptions

Openwebui Open Webui
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-12T16:04:58.200Z

Reserved: 2026-10-12T14:13:39.026Z

Link: CVE-2026-109300

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-12T17:17:23.700

Modified: 2026-10-12T17:17:23.700

Link: CVE-2026-109300

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-79

    Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')