CVE-2026-45665Public exploitNetwork attack vector

Session-token theft via post-sanitization Markdown parsing

Published May 15, 2026 · Updated May 15, 2026

Stored XSS in Open WebUI before 0.8.0 allows remote authenticated users with administrator access to steal a Super Admin session token. Banner.svelte sanitizes raw Markdown before marked.parse converts a javascript: link into HTML, then renders that unsanitized output with @html. Administrator access and a click by a banner viewer are required; execution exposes the viewer's active token, including the Super Admin's.

CVSS severity8.1
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Open WebUI before 0.8.0 allows remote authenticated users with administrator access to steal a Super Admin session token. Banner.svelte sanitizes raw Markdown before marked.parse converts a javascript: link into HTML, then renders that unsanitized output with @html. Administrator access and a click by a banner viewer are required; execution exposes the viewer's active token, including the Super Admin's.

The record

CVE
CVE-2026-45665
Published
May 15, 2026
Updated
May 15, 2026
Vendor
Open WebUI
Product
Open WebUI
Classifications
CWE-79, T1528
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. May 15, 2026CVE publishedPublication date reported by the CVE source.
  2. May 15, 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=< 0.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Open WebUI · Open WebUIversion=< 0.8.0

Published CVSS scores

8.1GitHubCVSS:3.1/AV:N/AC:L/PR:H/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.

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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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1528Steal Application Access Token

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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