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TI-2026-71111 Aliases CVE-2026-109295GHSA-9hcw-jmg5-2vcc

Regular expression denial of service in Open WebUI file search

Priority MEDIUM 57CWE-1333Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-1333.

Summary

Open WebUI from 0.11.0 before 0.11.4 contains a regular expression denial of service flaw, tracked as CWE-1333, that lets authenticated users stall server workers through file search patterns. An attacker can prompt the model to call grep_knowledge_files or grep_chat_files with a catastrophically backtracking regex, which blocks the event loop for two seconds per repeated call. Exploitation requires low privileges over the network and affects availability only.

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

Description from the CNA

Open WebUI from 0.11.0 before 0.11.4 contains a regular expression denial of service vulnerability that allows authenticated users to stall server workers via file search patterns. Attackers can instruct the model to call grep_knowledge_files or grep_chat_files with a catastrophically backtracking regex, blocking the event loop for two seconds per repeated call.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00328 26th percentileScored 2026-11-07
Fix Fixed open-webui (open-webui): 0.11.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

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-webui0.11.0 to before 0.11.40.11.4Patch availableCNA
  • open-webui Vendoropen-webui Affected 0.11.0 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 or later, which fixes the issue.

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
    Show all 19 records →

Timeline

  1. 2026-10-12 Threatist record created from CVE-2026-109295
  2. 2026-10-12 Alias added: GHSA-9hcw-jmg5-2vcc
  3. 2026-10-13 Priority changed: MEDIUM → LOW
  4. 2026-10-13 CISA SSVC decision points changed
  5. 2026-10-13 Priority changed: LOW → MEDIUM
  6. 2026-10-24 CVSS score changed · CNA

References

Advisory 1

  • 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

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences