PYSEC-2026-2970 Rattler vulnerable to package cache path traversal via conda package build string

rattlercache and py-rattler were vulnerable to package-cache path traversal when handling package metadata from conda channels. During cache materialization, the rattercache code used the package record build string as part of a cache key that was joined into a filesystem path. A malicious or...

PYSEC-2026-2705 Open WebUI has an IDOR vulnerability in the pin_channel_message API endpoint

Summary Pin/Unpin is a write operation modifies the message's ispinned , pinnedby, pinnedat fields, but in standard channels it only checks read permission, allowing users with read-only access to pin/unpin any message. Details...

Open WebUI has an IDOR vulnerability in the pin_channel_message API endpoint

SummaryPin/Unpin is a write operation modifies the message's ispinned , pinnedby, pinnedat fields, but in standard channels it only checks read permission, allowing users with read-only access to pin/unpin any message...

PYSEC-2026-2739 Open WebUI's Improper Authorization in Standard Channels Allows Message Updates with Read Permission

Vulnerability Description In standard channels i.e., channels whose channel.type is neither group nor dm, the endpoint POST /api/v1/channels/channelid/messages/messageid/update can be accessed with read permission only. When accesscontrol is set to None, the authorization check hasaccess...,...

Open WebUI's Improper Authorization in Standard Channels Allows Message Updates with Read Permission

Vulnerability DescriptionIn standard channels i.e., channels whose channel.type is neither group nor dm, the endpointPOST /api/v1/channels/channelid/messages/messageid/update can be accessed with read permission only.When accesscontrol is set to None, the authorization check hasaccess...,...

Open WebUI Missing Access Check on Channel Members Endpoint for Standard Channels

Missing Access Check on Channel Members Endpoint for Standard Channels Affected ComponentChannel members listing endpoint:- backend/openwebui/routers/channels.py lines 445-507, getchannelmembersbyid Affected VersionsCurrent main branch and likely all versions with the channels feature...

PYSEC-2026-2720 Open WebUI Missing Access Check on Channel Members Endpoint for Standard Channels

Missing Access Check on Channel Members Endpoint for Standard Channels Affected Component Channel members listing endpoint: - backend/openwebui/routers/channels.py lines 445-507, getchannelmembersbyid Affected Versions Current main branch and likely all versions with the channels feature...

PYSEC-2026-2732 Open WebUI: Deactivated Channel Members Retain Full Access to Group/DM Channels

Deactivated Channel Members Retain Full Access to Group/DM Channels Affected Component Channel membership authorization check: - backend/openwebui/models/channels.py lines 663-673, isuserchannelmember - Used at 15 locations in backend/openwebui/routers/channels.py Affected Versions Current main...

PYSEC-2026-2851 OpenEXR has buffer overflow in PyOpenEXR_old's channels() and channel()

Summary A memory safety bug in the legacy OpenEXR Python adapter the deprecated OpenEXR.InputFile wrapper allow crashes and likely code execution when opening attacker-controlled EXR files or when passing crafted Python objects. Integer overflow and unchecked allocation in InputFile.channel and...

Missing Authorization

Overview github.com/mattermost/mattermost/server/v8/channels/api4 is a platform for secure collaboration across the entire software development lifecycle Affected versions of this package are vulnerable to Missing Authorization via the scheme teams API endpoint. An attacker can access private tea...

EUVD-2026-43339

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to check the managesharedchannels permission in the /share-channel autocomplete handler, which allows an authenticated user without that permission to enumerate configured remote cluster connection metadata via slash...

CVE-2026-9824

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to check the managesharedchannels permission in the /share-channel autocomplete handler, which allows an authenticated user without that permission to enumerate configured remote cluster connection metadata via slash...

CVE-2026-9824 Remote cluster metadata enumeration via /share-channel autocomplete

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to check the managesharedchannels permission in the /share-channel autocomplete handler, which allows an authenticated user without that permission to enumerate configured remote cluster connection metadata via slash...

CVE-2026-9824 Remote cluster metadata enumeration via /share-channel autocomplete

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to check the managesharedchannels permission in the /share-channel autocomplete handler, which allows an authenticated user without that permission to enumerate configured remote cluster connection metadata via slash...

Incorrect Authorization

Overview github.com/mattermost/mattermost/server/v8/channels/api4 is a platform for secure collaboration across the entire software development lifecycle Affected versions of this package are vulnerable to Incorrect Authorization via a mismatch between the channel referenced in an action cookie a...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization via a mismatch between the channel referenced in an action cookie and the channel of the target post. An attacker can perform unauthorized interactive post actions in private channels by using a cookie obtained...

Missing Authorization

Overview Affected versions of this package are vulnerable to Missing Authorization due to insufficient restriction of the groupconstrained channel flag in the channel patch API. An attacker can remove all participants from a group or direct message conversation by enabling the groupconstrained fl...

Authorization Bypass Through User-Controlled Key

Overview Affected versions of this package are vulnerable to Authorization Bypass Through User-Controlled Key via the incoming webhook process. An attacker can impersonate another user and create posts or direct messages attributed to them by crafting specific webhook configurations and payloads...

Authentication Bypass by Primary Weakness

Overview github.com/mattermost/mattermost/server/channels/app is a private-cloud Slack alternative Affected versions of this package are vulnerable to Authentication Bypass by Primary Weakness in the OAuth refresh token grant process. An attacker can maintain unauthorized access by using a valid...

EUVD-2026-43311

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to restrict the groupconstrained channel flag to public and private channels that support group synchronization, which allows an ordinary group or direct message member to remove all participants from the conversation v...