Open WebUI up to 0.11.0 Tool Connection tools.py infinite loop

Summaryinfo

A vulnerability identified as critical has been detected in Open WebUI up to 0.11.0. This affects an unknown function of the file backend/open_webui/utils/tools.py of the component Tool Connection. This manipulation causes infinite loop. This vulnerability appears as CVE-2026-87015. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Open WebUI up to 0.11.0. It has been declared as critical. Affected by this vulnerability is some unknown functionality of the file backend/open_webui/utils/tools.py of the component Tool Connection. The manipulation with an unknown input leads to a infinite loop vulnerability. The CWE definition for the vulnerability is CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.6.27 until 0.11.1, backend/open_webui/utils/tools.py captured a cookie jar from the enclosing connection loop instead of binding it to each external tool callable. When multiple tool servers were attached and a session or system OAuth connection was processed last, a request to a different server configured for bearer authentication could include the calling user's Open WebUI session cookies, allowing that server's operator to reuse the session and take over the account. This issue is fixed in version 0.11.1.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-87015 since 09/08/2026. The exploitation appears to be easy. The attack can be launched remotely. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 0.11.1 eliminates this vulnerability.

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Productinfo

Name

• Open WebUI

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11.0

CPE 2.3info

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CPE 2.2info

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