CVE-2026-45665

High
8.1
0.05.010.0
Year
2026
Published
May 15, 2026
Known Affected Devices
0
CVSS Score
8.1

What is CVE-2026-45665?

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 Vector Breakdown

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

Exploitable remotely over the network without requiring access to the local system.

AC
Attack Complexity
Low

No special conditions required. Exploit can be performed reliably and repeatedly.

PR
Privileges Required
High

Administrative or root-level privileges required to exploit.

UI
User Interaction
Required

Victim must take an action (e.g. click a link, open a file) for the exploit to succeed.

S
Scope
Changed

Exploiting the vulnerability can affect other components beyond the vulnerable one.

C
Confidentiality Impact
High

Complete loss of confidentiality. All data on the component may be exposed.

I
Integrity Impact
High

Complete loss of integrity. Attacker can modify any file or data on the component.

A
Availability Impact
None

No availability impact. Service remains fully operational.

FAQ

How severe is CVE-2026-45665?

CVE-2026-45665 has a CVSS score of 8.1/10, rated as High. This is a high severity vulnerability and should be patched as soon as possible.

What does the CVSS score mean for CVE-2026-45665?

CVSS (Common Vulnerability Scoring System) rates vulnerability severity from 0.0 to 10.0. CVE-2026-45665 scores 8.1/10 (High). Scores 9.0–10.0 are Critical, 7.0–8.9 are High, 4.0–6.9 are Medium, and below 4.0 are Low.

Which devices are affected by CVE-2026-45665?

The list of devices confirmed to be affected by CVE-2026-45665 is shown in the "Affected Devices" section above. Check your firmware version against the vendor security advisory and apply the latest patch.

How do I fix or mitigate CVE-2026-45665?

Apply the latest firmware or software update from the vendor. Check the References section above for official advisories and patch notes. If no patch is available, consider disabling the affected feature or isolating the device from untrusted networks.