CVE-2026-70492: Open WebUI stored XSS vulnerability in math block rendering

# CVE-2026-70492: Open WebUI stored XSS vulnerability in math block rendering

https://gcdradar.vercel.app/incidents/cve-2026-70492-open-webui-stored-xss-vulnerability-in-math-b · AIR-2026-0057 · closed 2026-08-04

- Lane: Patch now
- Severity: 2 (Disclosed vulnerability)
- Fix status: Fix status unknown
- First reported: 2026-08-04
- AI role: Attack on AI
- Products: Open WebUI
- CVE ids: CVE-2026-70492
- CVSS: 8.7

## Summary

A rendering error in Open WebUI's KaTeX component allowed malicious chat messages to execute arbitrary script code in viewers' browsers. A fix has been issued to prevent session token theft.

## What to do

No action recorded; read the sources below and the vendor's advisory.

## Latest updates

- 2026-08-04: CVE-2026-70492: Open WebUI: Stored XSS via unescaped KaTeX render-error fallback in rendered messages (https://github.com/advisories/GHSA-pwxh-7358-jq2x)
- 2026-08-04: CVE-2026-70492: Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. (https://nvd.nist.gov/vuln/detail/CVE-2026-70492)

## Sources

- 2026-08-04 NVD: CVE-2026-70492: Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. https://nvd.nist.gov/vuln/detail/CVE-2026-70492
- 2026-08-04 GitHub Advisory Database: CVE-2026-70492: Open WebUI: Stored XSS via unescaped KaTeX render-error fallback in rendered messages https://github.com/advisories/GHSA-pwxh-7358-jq2x

Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.