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CVE-2026-54011

Openwebui Open Webui cross-site scripting (XSS)

8.7 HIGHPublic exploitEPSS 0.34%
  1. Published23 Jun 2026

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6,Open WebUI renders Mermaid blocks from Markdown files in the file preview panel and inserts the generated SVG into the DOM using innerHTML. Because Mermaid is configured with securityLevel: 'loose', attacker-controlled Mermaid content can be rendered unsafely in this flow. A working payload was validated through the Markdown preview path, resulting in JavaScript execution in the victim’s browser under the application origin. This vulnerability is fixed in 0.9.6.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredLow
User interactionRequired
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Affected products

Openwebui Open Webui< 0.9.6

Remediation

Fixed in
Openwebui Open Webui≥ 0.9.6

References

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Frequently asked

Is CVE-2026-54011 being actively exploited?

CVE-2026-54011 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.34%.

How severe is CVE-2026-54011?

CVE-2026-54011 has a CVSS 3.1 base score of 8.7, rated high. EPSS estimates a 0.34% probability of exploitation.

Which products are affected by CVE-2026-54011?

Affected products include Openwebui Open Webui.

How do I fix CVE-2026-54011?

Upgrade affected software to a fixed version, for example Openwebui Open Webui 0.9.6 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-54011 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.