[PR #24506] [MERGED] fix: enforce message ownership in group/DM channel update + delete endpoints #98727

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GiteaMirror · 2026-05-16T01:33:50-05:00

GiteaMirror commented

2026-05-16 01:33:50 -05:00

📋 Pull Request Information

Original PR: https://github.com/open-webui/open-webui/pull/24506
Author: @Classic298
Created: 5/9/2026
Status: ✅ Merged
Merged: 5/10/2026
Merged by: @tjbck

Base: dev ← Head: fix/channels-message-ownership-group-dm

📝 Commits (2)

9a8b955 fix: enforce message ownership in group/DM channel update + delete endpoints
1e5886b chore: trim comments

📊 Changes

1 file changed (+6 additions, -0 deletions)

View changed files

📝 backend/open_webui/routers/channels.py (+6 -0)

📄 Description

update_message_by_id (channels.py:1348) and delete_message_by_id (channels.py:1550) branch on channel.type. The else branch (standard channels) correctly enforces message.user_id != user.id ownership before mutating, but the if channel.type in ['group', 'dm'] branch only checked is_user_channel_member — channel membership alone, with no message ownership verification.

Effect on group/DM channels: any verified member of the conversation could:

overwrite another member's message content while the server preserved user_id=victim, producing tampered content that renders to other members as the original author's authentic post (integrity + authenticity);
silently delete another member's messages, removing them from conversation history without trace (integrity).

Reproduced end-to-end against v0.9.4 with three users (attacker, victim, viewer) sharing a group channel: attacker overwrites victim's message and deletes another, viewer reads the tampered content as victim-authored.

Two patches, identical shape, mirror the else branch's existing ownership semantics:

update_message_by_id group/DM branch: add if user.role != 'admin' and message.user_id != user.id: raise 403 immediately after the is_user_channel_member check.
delete_message_by_id group/DM branch: same.

The standard-channel branch is unchanged (it already enforced ownership). Admins remain able to moderate any message, matching the existing semantic in the standard-channel branch.

Contributor License Agreement

By submitting this pull request, I confirm that I have read and fully agree to the Contributor License Agreement (CLA), and I am providing my contributions under its terms.

Note

Deleting the CLA section will lead to immediate closure of your PR and it will not be merged in.

_{🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.}

## 📋 Pull Request Information **Original PR:** https://github.com/open-webui/open-webui/pull/24506 **Author:** [@Classic298](https://github.com/Classic298) **Created:** 5/9/2026 **Status:** ✅ Merged **Merged:** 5/10/2026 **Merged by:** [@tjbck](https://github.com/tjbck) **Base:** `dev` ← **Head:** `fix/channels-message-ownership-group-dm` --- ### 📝 Commits (2) - [`9a8b955`](https://github.com/open-webui/open-webui/commit/9a8b955e63314575612720dd547a94cfeae94901) fix: enforce message ownership in group/DM channel update + delete endpoints - [`1e5886b`](https://github.com/open-webui/open-webui/commit/1e5886b8300660b95522fec2eda3683b4b78ffc7) chore: trim comments ### 📊 Changes **1 file changed** (+6 additions, -0 deletions) <details> <summary>View changed files</summary> 📝 `backend/open_webui/routers/channels.py` (+6 -0) </details> ### 📄 Description `update_message_by_id` (channels.py:1348) and `delete_message_by_id` (channels.py:1550) branch on `channel.type`. The `else` branch (standard channels) correctly enforces `message.user_id != user.id` ownership before mutating, but the `if channel.type in ['group', 'dm']` branch only checked `is_user_channel_member` — channel membership alone, with no message ownership verification. Effect on group/DM channels: any verified member of the conversation could: - overwrite another member's message content while the server preserved `user_id=victim`, producing tampered content that renders to other members as the original author's authentic post (integrity + authenticity); - silently delete another member's messages, removing them from conversation history without trace (integrity). Reproduced end-to-end against v0.9.4 with three users (attacker, victim, viewer) sharing a group channel: attacker overwrites victim's message and deletes another, viewer reads the tampered content as victim-authored. Two patches, identical shape, mirror the `else` branch's existing ownership semantics: - `update_message_by_id` group/DM branch: add `if user.role != 'admin' and message.user_id != user.id: raise 403` immediately after the `is_user_channel_member` check. - `delete_message_by_id` group/DM branch: same. The standard-channel branch is unchanged (it already enforced ownership). Admins remain able to moderate any message, matching the existing semantic in the standard-channel branch. ### Contributor License Agreement  - [x] By submitting this pull request, I confirm that I have read and fully agree to the [Contributor License Agreement (CLA)](https://github.com/open-webui/open-webui/blob/main/CONTRIBUTOR_LICENSE_AGREEMENT), and I am providing my contributions under its terms. > [!NOTE] > Deleting the CLA section will lead to immediate closure of your PR and it will not be merged in. --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>

GiteaMirror added the pull-request label 2026-05-16 01:33:50 -05:00

GiteaMirror closed this issue

2026-05-16 01:33:54 -05:00

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Reference: github-starred/open-webui#98727