Open WebUI up to 0.11.0 Message-Chain Reconstruction Helper misc.py resource consumption

Summaryinfo

A vulnerability was found in Open WebUI up to 0.11.0. It has been rated as problematic. This impacts an unknown function of the file backend/open_webui/utils/misc.py of the component Message-Chain Reconstruction Helper. This manipulation causes resource consumption. This vulnerability is registered as CVE-2026-88002. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as problematic was found in Open WebUI up to 0.11.0. Affected by this vulnerability is an unknown function of the file backend/open_webui/utils/misc.py of the component Message-Chain Reconstruction Helper. The manipulation with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. The summary by CVE is:

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.5.0 until 0.11.1, the message-chain reconstruction helper in backend/open_webui/utils/misc.py advanced through a chat history by map key but tracked visited entries using each message body's optional id field. An authenticated user could store id-less messages in a parent cycle and trigger a non-terminating walk that blocked the async event loop, grew memory until termination, and remained persistent across process restarts. This issue is fixed in version 0.11.1.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-88002 since 09/09/2026. The exploitation appears to be easy. The attack can be launched remotely. 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.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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