CVE-2026-59714 open-webui CVE debrief

Who should care

Defenders responsible for Open WebUI deployments should assess exposure and prioritize verification and remediation efforts. This includes administrators and security teams managing self-hosted AI platforms, especially those using versions prior to 0.10.0.

Why it matters

CVE-2026-59714 is a high-severity vulnerability in Open WebUI that allows authenticated users to overwrite message content in unauthorized channels. Defenders should prioritize verification of exposure, assess potential impact, and apply the fix in version 0.10.0 to prevent potential unauthorized modifications and maintain data integrity.

• Potential unauthorized modification of message content in private or DM channels.
• Risk of targeted attacks on specific users or channels.
• Need for verification of user authentication and authorization controls.
• Potential impact on compliance and data integrity in regulated environments.

Technical summary

The vulnerability in Open WebUI allows authenticated users to overwrite message content in channels they do not belong to by sending a chat completion request with a specially crafted channel:-prefixed chat_id and target message_id. This is possible because the _make_channel_emitter pipeline writes to the Messages table using the caller-supplied message_id without binding it to the channel. The issue is fixed in version 0.10.0, and defenders should prioritize verifying exposure and assessing the impact of this vulnerability on their systems, especially those using Open WebUI versions prior to 0.10.0. The vulnerability has a CVSS score of 7.1 and is considered HIGH severity.

Defensive priority

Defenders should prioritize verifying exposure and assessing the impact of this vulnerability on their systems, especially those using Open WebUI versions prior to 0.10.0.

Recommended defensive actions

• Verify if the system uses Open WebUI and check the version to determine if it is vulnerable.
• Assess user authentication and authorization controls to prevent unauthorized channel access.
• Upgrade to Open WebUI version 0.10.0 or later to apply the fix.
• Monitor for suspicious chat completion requests that could indicate exploitation attempts.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The vulnerability is confirmed in Open WebUI versions from 0.9.5 up to but not including 0.10.0. The issue allows authenticated users to overwrite message content in unauthorized channels by exploiting the _make_channel_emitter pipeline. Official sources confirm the fix in version 0.10.0.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.