CVE-2026-70492Public exploitNetwork attack vectorHinoki check available

Stored XSS via unescaped KaTeX error fallback

Published Aug 4, 2026 · Updated Aug 4, 2026

Stored XSS in Open WebUI 0.10.0 through 0.10.2 allows remote authenticated users to execute script in a message viewer's browser. The KaTeX renderer catches a stack overflow from deeply nested math and sends the untouched math source to an HTML insertion sink without escaping it. A normal account and a viewer opening the crafted message are required; the script can steal the viewer's local session token and take over that account.

CVSS severity8.7
High
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Stored XSS in Open WebUI 0.10.0 through 0.10.2 allows remote authenticated users to execute script in a message viewer's browser. The KaTeX renderer catches a stack overflow from deeply nested math and sends the untouched math source to an HTML insertion sink without escaping it. A normal account and a viewer opening the crafted message are required; the script can steal the viewer's local session token and take over that account.

The record

CVE
CVE-2026-70492
Published
Aug 4, 2026
Updated
Aug 4, 2026
Vendor
Open WebUI
Product
Open WebUI
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 0.10.0, < 0.11.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Open WebUI · Open WebUIversion=>= 0.10.0, < 0.11.0

Published CVSS scores

8.7GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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