CVE-2026-45665: Openwebui Open Webui cross-site scripting (XSS) (CVSS 8.1)

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.0, a Stored Cross-Site Scripting (XSS) vulnerability exists in the Banner component due to an improper sanitization order (specifically, DOMPurify is executed before the marked library). This vulnerability allows a compromised or malicious administrator to plant a malicious payload in the global banner. Crucially, this vector enables Privilege Escalation, as the malicious banner is rendered for all users, including the Super Admin (Primary Admin). Consequently, the payload successfully bypasses the existing security mechanism. An attacker can leverage this to steal the Super Admin's session token This vulnerability is fixed in 0.8.0.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredHigh

User interactionRequired

ScopeChanged

ConfidentialityHigh

IntegrityHigh

AvailabilityNone

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

Affected products

Openwebui Open Webui< 0.8.0

Remediation

Fixed in

Openwebui Open Webui≥ 0.8.0

Patch & vendor advisories

https://github.com/open-webui/open-webui/security/advisories/GHSA-cqp4-qqvg-3787

References

https://github.com/open-webui/open-webui/security/advisories/GHSA-cqp4-qqvg-3787ExploitMitigationVendor Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-45665 being actively exploited?

CVE-2026-45665 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.38%.

How severe is CVE-2026-45665?

CVE-2026-45665 has a CVSS 3.1 base score of 8.1, rated high. EPSS estimates a 0.38% probability of exploitation.

Which products are affected by CVE-2026-45665?

Affected products include Openwebui Open Webui.

How do I fix CVE-2026-45665?

Upgrade affected software to a fixed version, for example Openwebui Open Webui 0.8.0 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-45665 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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