Open WebUI: Cross-channel message overwrite via chat completion API (single-model and multimodel message_ids) (CVE-2026-59714) | HOL Guard CVE

High · CVSS 7.1CVE-2026-59714

Open WebUI: Cross-channel message overwrite via chat completion API (single-model and multimodel message_ids)

Answer in brief

CVE-2026-59714 records a High severity (CVSS 7.1) vulnerability in Open WebUI: Cross-channel message overwrite via chat completion API (single-model and multimodel message_ids). The current sources do not mark it as known exploited. The current feed maps open-webui/open-webui (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 13, 2026Updated Sep 18, 2026Source checked Sep 28, 2026First seen by HOL Aug 13, 2026Material review Sep 18, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.1
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 7.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps open-webui/open-webui (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
open-webui/open-webuigeneric	>=0.9.5 <0.10.0	0.10.0

Recommended response

Check inventory. Check lockfiles and deployed manifests for open-webui/open-webui.
Review the reported fix. Update open-webui/open-webui to 0.10.0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 13, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 18, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 13, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.