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CVE-2026-70492

Open WebUI: Stored XSS via unescaped KaTeX render-error fallback in rendered messages

Published: Aug 4, 2026Updated: Aug 5, 2026 Sources: CVE List NVDCWE-79
8.7HIGH
NVD MITRE
EPSS Score
0.3%
Top 82.3%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
Not available

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:RS:CC:HI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:RUser Interaction
Required
Scope
S:CScope
Changed
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:NAvailability
None
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Weaknesses

CWE-79

Affected Products

open-webui
oss-projectaka open-webui/open-webui
open-webuiOn-premWeb App
AI / ML / ai-agent-tooling

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Execution
Initial Access
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References

https://github.com/open-webui/open-webui/security/advisories/GHSA-pwxh-7358-jq2x
github.com
https://github.com/open-webui/open-webui/pull/26718
github.com
https://github.com/open-webui/open-webui/commit/bc600d3f085802c45aa8f38c30e6e8c986bde6cc
github.com
and 1 more references View all →

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