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Stored XSS in Open WebUI citation embed_url lets attackers steal sessions

Priority LOW 39CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

Open WebUI from 0.6.33 before 0.11.4 contains a cross-site scripting flaw (CWE-79) in citation embed_url fields. An authenticated user can store javascript: URLs there, and a crafted shared chat passes the citation to window.open when clicked. A victim who clicks it can have the attacker's script run in their session and read localStorage.token, acting as the victim.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

Open WebUI from 0.6.33 before 0.11.4 contains a cross-site scripting vulnerability that allows authenticated users to execute script in victims' sessions by storing javascript: URLs in citation embed_url fields. Attackers can share a crafted chat whose citation, when clicked, is passed to window.open, letting them steal localStorage.token and act as the victim.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00279 20th percentileScored 2026-11-07
Fix Fixed open-webui (open-webui): 0.11.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
open-webuiopen-webui0.6.33 to before 0.11.40.11.4Patch availableCNA
  • open-webui Vendoropen-webui Affected 0.6.33 to before 0.11.4 Fixed in 0.11.4 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*——open-webui
  • cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* Versions — — ·open-webui

Remediation

Upgrade Open WebUI to version 0.11.4, which fixes the flaw.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA open-webui (open-webui) Fixed in 0.11.4

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    open-webui 0.11.4

    19 records Highest priority Priority HIGH 3 HIGH, 8 MEDIUM, 8 LOW

    Other records, highest priority first

    • TI-2026-71106 Stored cross-site scripting in Open WebUI via DOCX previewPriority HIGH 72
    • TI-2026-71108 Session cookie disclosure in Open WebUI OAuth-mode connectionsPriority HIGH 68
    • TI-2026-71104 Stored cross-site scripting in Open WebUI markdown linksPriority HIGH 67

Timeline

  1. 2026-10-12 Threatist record created from CVE-2026-109291
  2. 2026-10-12 Alias added: GHSA-g5hc-j8wv-8p98
  3. 2026-10-13 Priority changed: MEDIUM → LOW
  4. 2026-10-18 CISA SSVC decision points changed

References

  • TI-2024-06216 Open WebUI Arbitrary File Upload + Path Traversal CVSS 3.1HIGH 8.8
  • TI-2024-07467 Improper Authentication in open-webui/open-webui CVSS 3.1HIGH 8.2
  • TI-2026-42359 Open WebUI: Cross-user code-interpreter and tool execution via unvalidated Socket.IO event-caller session_id CVSS 3.1CRITICAL 9.0
  • TI-2026-40759 open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation CVSS 4.0CRITICAL 9.0
  • TI-2024-07431 Cross-site Scripting (XSS) in open-webui/open-webui CVSS 3.0CRITICAL 9.0
  • TI-2026-60021 Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin CVSS 3.1HIGH 8.7
See all 175 →

Sources