PYSEC-2026-2720

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Import Source
https://github.com/pypa/advisory-database/blob/main/vulns/open-webui/PYSEC-2026-2720.yaml
JSON Data
https://api.osv.dev/v1/vulns/PYSEC-2026-2720
Aliases
Published
2026-07-13T15:15:42Z
Modified
2026-07-13T16:32:19Z
Severity
  • 4.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N CVSS Calculator
Summary
Open WebUI Missing Access Check on Channel Members Endpoint for Standard Channels
Details

Missing Access Check on Channel Members Endpoint for Standard Channels

Affected Component

Channel members listing endpoint:

  • backend/open_webui/routers/channels.py (lines 445-507, get_channel_members_by_id)

Affected Versions

Current main branch and likely all versions with the channels feature.

Description

The GET /api/v1/channels/{id}/members endpoint only checks membership for group and dm channel types (lines 467-469). For standard channels — including private ones — there is no channel_has_access check before returning the member list. Any authenticated user who knows a private channel's UUID can enumerate all users with access to that channel.

# Line 467-469: only group/dm channels are checked
if channel.type in ['group', 'dm']:
    if not Channels.is_user_channel_member(channel.id, user.id, db=db):
        raise HTTPException(...)
# Standard channels fall through with NO access check

Compare with other channel endpoints (e.g., get_channel_messages at line 688) which correctly call channel_has_access(user.id, channel, permission='read') for standard channels.

CVSS 3.1 Breakdown

Metric Value Rationale
Attack Vector Network (N) Exploited remotely via API call
Attack Complexity Low (L) Single API call, no special conditions
Privileges Required Low (L) Requires a valid user account
User Interaction None (N) No victim interaction required
Scope Unchanged (U) Impact is within the channel authorization boundary
Confidentiality Low (L) Leaks user identities and details for a private channel
Integrity None (N) No data modification
Availability None (N) No denial of service

Attack Scenario

  1. Attacker obtains a private standard channel's UUID (via logs, browser history, URL observation, or other API responses).
  2. Attacker calls GET /api/v1/channels/{id}/members.
  3. The server returns the full list of permitted users including their IDs, names, emails, roles, and profile images.
  4. The attacker has no access to the channel's messages (those endpoints check access correctly), but now knows exactly who does.

Impact

  • Leaks the identity and personal details of every user with access to a private channel
  • Reveals organizational structure and project assignments
  • Enables targeted social engineering against channel members

Preconditions

  • Channels feature must be enabled (disabled by default)
  • Attacker must know the channel UUID (not guessable, but obtainable through indirect means)
References

Affected packages

PyPI / open-webui

Package

Name
open-webui
View open source insights on deps.dev
Purl
pkg:pypi/open-webui

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
0.9.0

Affected versions

0.*
0.1.124
0.1.125
0.2.0
0.2.1
0.2.2
0.2.3
0.2.4
0.2.5
0.3.0
0.3.1
0.3.2
0.3.3
0.3.4
0.3.5
0.3.6
0.3.7
0.3.8
0.3.9
0.3.10
0.3.12
0.3.13
0.3.14
0.3.15
0.3.16
0.3.17.dev2
0.3.17.dev3
0.3.17.dev4
0.3.17.dev5
0.3.17
0.3.18
0.3.19
0.3.20
0.3.21
0.3.22
0.3.23
0.3.24
0.3.25
0.3.26
0.3.27.dev1
0.3.27.dev2
0.3.27.dev3
0.3.27
0.3.28
0.3.29
0.3.30.dev1
0.3.30.dev2
0.3.30
0.3.31.dev1
0.3.31
0.3.32
0.3.33.dev1
0.3.33
0.3.34
0.3.35
0.4.0.dev1
0.4.0.dev2
0.4.0
0.4.1
0.4.2
0.4.3
0.4.4
0.4.5
0.4.6.dev1
0.4.6
0.4.7
0.4.8
0.5.0.dev1
0.5.0.dev2
0.5.0
0.5.1
0.5.2
0.5.3.dev1
0.5.3
0.5.4
0.5.5
0.5.6
0.5.7
0.5.8
0.5.9
0.5.10
0.5.11
0.5.12
0.5.13
0.5.14
0.5.15
0.5.16
0.5.17
0.5.18
0.5.19
0.5.20
0.6.0
0.6.1
0.6.2
0.6.3
0.6.4
0.6.5
0.6.6.dev1
0.6.6
0.6.7
0.6.8
0.6.9
0.6.10
0.6.11
0.6.12
0.6.13
0.6.14
0.6.15
0.6.16
0.6.18
0.6.19
0.6.20
0.6.21
0.6.22
0.6.23
0.6.24
0.6.25
0.6.26.dev1
0.6.26
0.6.27
0.6.28
0.6.29
0.6.30
0.6.31
0.6.32
0.6.33
0.6.34
0.6.35
0.6.36
0.6.37
0.6.38
0.6.39
0.6.40
0.6.41
0.6.42
0.6.43
0.7.0
0.7.1
0.7.2
0.8.0
0.8.1
0.8.2
0.8.3
0.8.4
0.8.5
0.8.6
0.8.7
0.8.8
0.8.9
0.8.10
0.8.11
0.8.12

Database specific

source 
"https://github.com/pypa/advisory-database/blob/main/vulns/open-webui/PYSEC-2026-2720.yaml"