---
cve: "CVE-2026-70492"
severity: "HIGH"
cvss: 8.7
epss: "0.4%"
vendor: "open-webui"
kev: false
exploited: false
published: "2026-08-04 21:16:38"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-11-09T15:41:35+01:00"
---

# CVE-2026-70492

> 8.7 HIGH · 🧪 PoC

## Beschreibung

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.

## CNA-Record (Kanon, cvelistV5)

- CNA: **GitHub_M**
- State: PUBLISHED
- Stand: 2026-08-05 14:41:30
- CNA-CVSS: **8.7** (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Erforderlich | good |
| S Scope | Verändert | bad |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Keine | good |

## Schwachstellen-Klasse

- **CWE-79** — Improper Neutralization of Input During Web Page Generation (Cross-site Scripting)
  The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

## Angriffsmuster (CAPEC)

- [CAPEC-63 — Cross-Site Scripting (XSS)](https://capec.mitre.org/data/definitions/63.html) _(Severity: Very High)_
- [CAPEC-85 — AJAX Footprinting](https://capec.mitre.org/data/definitions/85.html) _(Severity: Low)_
- [CAPEC-209 — XSS Using MIME Type Mismatch](https://capec.mitre.org/data/definitions/209.html) _(Severity: Medium)_
- [CAPEC-588 — DOM-Based XSS](https://capec.mitre.org/data/definitions/588.html) _(Severity: Very High)_
- [CAPEC-591 — Reflected XSS](https://capec.mitre.org/data/definitions/591.html) _(Severity: Very High)_
- [CAPEC-592 — Stored XSS](https://capec.mitre.org/data/definitions/592.html) _(Severity: Very High)_

## Patch verfügbar (OSV)

- f9590b8017199e56d5e953657e6498e3cef1d246 (Commit)
- bc600d3f085802c45aa8f38c30e6e8c986bde6cc (Commit)

## Referenzen

- <https://github.com/open-webui/open-webui/security/advisories/GHSA-pwxh-7358-jq2x>
- <https://github.com/open-webui/open-webui/pull/26718>
- <https://github.com/open-webui/open-webui/commit/bc600d3f085802c45aa8f38c30e6e8c986bde6cc>
- <https://github.com/open-webui/open-webui/releases/tag/v0.11.0>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-70492/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_