CVE-2026-70492 — Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform.¶
Key facts
CVE-2026-70492 is a High (8.7) vulnerability: Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform.. This entry ships a detection-only PoC and a Docker test lab.
| CVE | CVE-2026-70492 |
| Severity | High (8.7) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-70492/ |
Details¶
English | 한국어
Description¶
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.0, src/lib/components/chat/Messages/Markdown/KatexRenderer.svelte could store and render a chat message whose math block makes KaTeX fail with a stack overflow instead of a parse error. The catch branch fell back to inserting the original math source into the page as HTML through {@html} rather than as text, so script in the message runs in the browser of whoever views it, including shared chats and channels. The viewer's session token in localStorage can be stolen, and an administrator viewer can have their account taken over. This issue is fixed in 0.11.0.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2026-70492 |
| Type | XSS |
| CVSS Score | 8.7 |
Proof of Concept¶
Download¶
# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-70492/poc.py
Usage¶
# Run PoC against target
python3 poc.py --target <TARGET_URL>
# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>
⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.
Test Lab¶
This repository includes a Docker-based test environment with both vulnerable and patched applications.
Quick Start¶
# Clone and navigate to CVE directory
cd CVE-2026-70492
# Start both applications
docker-compose up -d
# Run tests
./run-tests.sh # Linux/Mac
./run-tests.ps1 # Windows PowerShell
Application Endpoints¶
| Application | URL | Status |
|---|---|---|
| Vulnerable App | http://localhost:8080 | Shows vulnerability |
| Patched App | http://localhost:8081 | Demonstrates fix |
Directory Structure¶
├── README.md # English documentation
├── README_KO.md # Korean documentation
├── poc.py # PoC detection script
├── docker-compose.yml # Container orchestration
├── run-tests.sh # Linux/Mac test runner
├── run-tests.ps1 # Windows test runner
├── vulnerable-app/ # Vulnerable version
│ ├── app.py
│ ├── Dockerfile
│ └── requirements.txt
└── patched-app/ # Fixed version
├── app.py
├── Dockerfile
└── requirements.txt
References¶
- https://github.com/open-webui/open-webui/commit/bc600d3f085802c45aa8f38c30e6e8c986bde6cc
- https://github.com/open-webui/open-webui/pull/26718
- https://github.com/open-webui/open-webui/releases/tag/v0.11.0
- https://github.com/open-webui/open-webui/security/advisories/GHSA-pwxh-7358-jq2x
- https://github.com/open-webui/open-webui/security/advisories/GHSA-pwxh-7358-jq2x
Generated by PoC Generator on 2026-08-10T08:57:15.895511913
Frequently asked questions¶
What is CVE-2026-70492?¶
CVE-2026-70492 is a High (8.7) vulnerability: Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform.. This entry ships a detection-only PoC and a Docker test lab.
How do I detect CVE-2026-70492?¶
Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.
How do I block or mitigate CVE-2026-70492?¶
Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.
For authorized security testing and research only. See the full source and NVD record.