CVE-2026-45399

High
7.1
0.05.010.0
Year
2026
Published
May 15, 2026
Known Affected Devices
0
CVSS Score
7.1

What is CVE-2026-45399?

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, any authenticated user with low privileges can enumerate active background tasks across the system and stop tasks belonging to other users via the GET /api/tasks and POST /api/tasks/stop/{task_id} methods. This allows a casual user to disrupt system-wide chat usage by continuously canceling other users' active tasks. This is a real authorization vulnerability affecting integrity and usability in multi-user deployments. This vulnerability is fixed in 0.9.0.

CVSS Vector Breakdown

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

Basic user account required (e.g. standard login without admin rights).

UI
User Interaction
None

No user interaction required. Exploit runs without any victim action.

S
Scope
Unchanged

Exploiting the vulnerability only affects the vulnerable component itself.

C
Confidentiality Impact
Low

Some sensitive information is disclosed, but attacker has limited access.

I
Integrity Impact
None

No integrity impact. Data cannot be modified.

A
Availability Impact
High

Complete denial of service. The component becomes fully unavailable.

FAQ

How severe is CVE-2026-45399?

CVE-2026-45399 has a CVSS score of 7.1/10, 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-2026-45399?

CVSS (Common Vulnerability Scoring System) rates vulnerability severity from 0.0 to 10.0. CVE-2026-45399 scores 7.1/10 (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-2026-45399?

The list of devices confirmed to be affected by CVE-2026-45399 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-2026-45399?

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.