PYSEC-2026-2739
Vulnerability from pysec - Published: 2026-07-13 15:15 - Updated: 2026-07-13 16:05Vulnerability Description
In standard channels (i.e., channels whose channel.type is neither group nor dm), the endpoint
POST /api/v1/channels/{channel_id}/messages/{message_id}/update can be accessed with read permission only.
When access_control is set to None, the authorization check has_access(..., type="read") evaluates to True, allowing users who are not the message owner to update messages.
As a result, unauthorized modification of other users’ messages is possible.
Attack Prerequisites
- The attacker is an authenticated user (role
useror higher) - The target channel is a standard channel (i.e., not
groupordm) access_controlisNoneor allowsreadaccess- The attacker can obtain the target
message_id(e.g., via the channel’s message list)
Attack Scenario
- The attacker (User B) retrieves another user’s
message_idfrom the message list in a standard channel -
The attacker sends a request to
POST /api/v1/channels/{channel_id}/messages/{message_id}/update -
The message authored by another user (User A) is successfully updated
Potential Impact
- Unauthorized modification of other users’ messages (violation of data integrity)
Steps to Reproduce
- Log in as an administrator
- Create User A
- Create User B
- Log in as User A
- Log in as User B
- As the administrator, create a new channel
- As User A, post a new message in the channel
- As User B, edit User A’s message
- Confirm that User A’s message has been modified without authorization
Affected Files and Line Numbers
-
backend/open_webui/routers/channels.py:1417–1460The authorization check in
update_message_by_idallows access with read permission -
backend/open_webui/utils/access_control.py:124–135When
access_control=Noneandstrict=True, read access is permitted -
backend/open_webui/models/messages.py:341–358The update logic does not enforce any message ownership check
Recommended Mitigation
Update the condition in
backend/open_webui/routers/channels.py:1451–1456
by changing the permission check from read to write, so that only administrators, message owners, or users with write permission can update messages.
Proposed Changes
-
For standard channels, change the update permission requirement from
has_access(..., type="read")tohas_access(..., type="write") -
Preserve the existing ownership check (
message.user_id == user.id)
AI Usage
- Translation from Japanese to English
- CWE classification and assessment
- Affected Files and Line Numbers
| Name | purl | open-webui | pkg:pypi/open-webui |
|---|
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "open-webui",
"purl": "pkg:pypi/open-webui"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.8.6"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"0.1.124",
"0.1.125",
"0.2.0",
"0.2.1",
"0.2.2",
"0.2.3",
"0.2.4",
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"0.3.18",
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"0.3.21",
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"0.4.6",
"0.4.6.dev1",
"0.4.7",
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"0.5.0",
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"0.5.0.dev2",
"0.5.1",
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"0.5.16",
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"0.5.3.dev1",
"0.5.4",
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"0.5.6",
"0.5.7",
"0.5.8",
"0.5.9",
"0.6.0",
"0.6.1",
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"0.6.13",
"0.6.14",
"0.6.15",
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"0.6.2",
"0.6.20",
"0.6.21",
"0.6.22",
"0.6.23",
"0.6.24",
"0.6.25",
"0.6.26",
"0.6.26.dev1",
"0.6.27",
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"0.6.3",
"0.6.30",
"0.6.31",
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"0.6.35",
"0.6.36",
"0.6.37",
"0.6.38",
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"0.6.41",
"0.6.42",
"0.6.43",
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"0.8.0",
"0.8.1",
"0.8.2",
"0.8.3",
"0.8.4",
"0.8.5"
]
}
],
"aliases": [
"CVE-2026-44571",
"GHSA-jgj3-r8hr-9pjw"
],
"details": "## Vulnerability Description\n\nIn standard channels (i.e., channels whose `channel.type` is neither `group` nor `dm`), the endpoint\n\n`POST /api/v1/channels/{channel_id}/messages/{message_id}/update` can be accessed with **read permission only**.\n\nWhen `access_control` is set to `None`, the authorization check `has_access(..., type=\"read\")` evaluates to `True`, allowing users who are **not the message owner** to update messages.\n\nAs a result, unauthorized modification of other users\u2019 messages is possible.\n\n---\n\n## Attack Prerequisites\n\n- The attacker is an authenticated user (role `user` or higher)\n- The target channel is a standard channel (i.e., not `group` or `dm`)\n- `access_control` is `None` or allows `read` access\n- The attacker can obtain the target `message_id` (e.g., via the channel\u2019s message list)\n\n\n\n## Attack Scenario\n\n1. The attacker (User B) retrieves another user\u2019s `message_id` from the message list in a standard channel\n2. The attacker sends a request to\n \n `POST /api/v1/channels/{channel_id}/messages/{message_id}/update`\n \n3. The message authored by another user (User A) is successfully updated\n\n\n\n## Potential Impact\n\n- Unauthorized modification of other users\u2019 messages (violation of data integrity)\n\n\n# Steps to Reproduce\n\n1. Log in as an administrator\n\n\u003cimg width=\"3334\" height=\"1668\" alt=\"image\" src=\"https://github.com/user-attachments/assets/b20323d3-c050-4438-8912-193a417654bc\" /\u003e\n\n\n2. Create User A\n\n\u003cimg width=\"3346\" height=\"788\" alt=\"image\" src=\"https://github.com/user-attachments/assets/b9e4fb8a-b14e-4a4b-b012-02ccfba52fca\" /\u003e\n\n3. Create User B\n\n\u003cimg width=\"3354\" height=\"796\" alt=\"image\" src=\"https://github.com/user-attachments/assets/f3cf6892-e6c9-4778-b471-f1cc0deec6c8\" /\u003e\n\n\n4. Log in as User A\n\n\u003cimg width=\"3360\" height=\"1668\" alt=\"image\" src=\"https://github.com/user-attachments/assets/5264ee07-f5c5-4bbe-ad4f-da69fb540fc9\" /\u003e\n\n\n5. Log in as User B\n\n\u003cimg width=\"3354\" height=\"1670\" alt=\"image\" src=\"https://github.com/user-attachments/assets/f112f8e8-b3e2-4e65-b226-c7b6c986f3bb\" /\u003e\n\n\n6. As the administrator, create a new channel\n\n\u003cimg width=\"2582\" height=\"988\" alt=\"image\" src=\"https://github.com/user-attachments/assets/bc012d9a-f884-4c83-b6bb-d1e5399f61bb\" /\u003e\n\n\n7. As User A, post a new message in the channel\n\n\u003cimg width=\"2626\" height=\"962\" alt=\"image\" src=\"https://github.com/user-attachments/assets/d7ff12c2-fe17-44f0-aaf9-5ce2bac9a378\" /\u003e\n\n\n8. As User B, edit User A\u2019s message\n\n\u003cimg width=\"2604\" height=\"958\" alt=\"image\" src=\"https://github.com/user-attachments/assets/8e19ec3e-fdda-4d36-acd5-f3e1fd3402dd\" /\u003e\n\n\n9. Confirm that User A\u2019s message has been modified without authorization\n\n\u003cimg width=\"2378\" height=\"1976\" alt=\"image\" src=\"https://github.com/user-attachments/assets/6415fd41-ac68-4d42-83c9-6297caee1fb4\" /\u003e\n\n\n## Affected Files and Line Numbers\n\n- `backend/open_webui/routers/channels.py:1417\u20131460`\n \n The authorization check in `update_message_by_id` allows access with **read** permission\n \n- `backend/open_webui/utils/access_control.py:124\u2013135`\n \n When `access_control=None` and `strict=True`, **read** access is permitted\n \n- `backend/open_webui/models/messages.py:341\u2013358`\n \n The update logic does not enforce any message ownership check\n \n\n## Recommended Mitigation\n\nUpdate the condition in\n\n`backend/open_webui/routers/channels.py:1451\u20131456`\n\nby changing the permission check from **`read`** to **`write`**, so that only administrators, message owners, or users with write permission can update messages.\n\n### Proposed Changes\n\n- For standard channels, change the update permission requirement from\n \n `has_access(..., type=\"read\")` to `has_access(..., type=\"write\")`\n \n- Preserve the existing ownership check (`message.user_id == user.id`)\n\n## **AI Usage**\n\n- Translation from Japanese to English\n- CWE classification and assessment\n- Affected Files and Line Numbers",
"id": "PYSEC-2026-2739",
"modified": "2026-07-13T16:05:13.532052Z",
"published": "2026-07-13T15:15:43.914937Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-jgj3-r8hr-9pjw"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44571"
},
{
"type": "PACKAGE",
"url": "https://github.com/open-webui/open-webui"
},
{
"type": "PACKAGE",
"url": "https://pypi.org/project/open-webui"
},
{
"type": "ADVISORY",
"url": "https://github.com/advisories/GHSA-jgj3-r8hr-9pjw"
}
],
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "Open WebUI\u0027s Improper Authorization in Standard Channels Allows Message Updates with Read Permission"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.