# CVE-2026-109295: Open WebUI 0.11.0 before 0.11.4 ReDoS via grep_knowledge_files Event Loop

> Authenticated users can cause denial of service in Open WebUI by submitting malicious regex patterns that stall server workers.

- **Severity:** Medium 5.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** GHSA-9hcw-jmg5-2vcc, GHSA-gfjp-5hc9-852r

## What is CVE-2026-109295?

CVE-2026-109295 is a medium-severity denial of service vulnerability in open-webui, published on 12 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official 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.

Weakness: CWE-1333 (Inefficient Regular Expression Complexity)

## Which versions are affected by CVE-2026-109295?


## How do I fix CVE-2026-109295?

No fix has been published for CVE-2026-109295 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-109295 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-109295 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-109295 and fix it if it is affected.

What it is: CVE-2026-109295 is a medium-severity denial of service vulnerability in open-webui, published on 12 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-109295 exists.

Affected product: open-webui. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-109295/ (Markdown: https://insights.sbomify.com/CVE-2026-109295/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-109295
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109295
- OSV: https://osv.dev/vulnerability/CVE-2026-109295

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-109295/
Summaries are generated and may contain mistakes; the official description above is the record.