45 matches found
CVE-2026-9824
Mattermost v11.7.x ≤ 11.7.2, v11.6.x ≤ 11.6.4, and v10.11.x ≤ 10.11.19 are affected by CVE-2026-9824 due to a missing check of the manage_shared_channels permission in the /share-channel autocomplete handler. This allows an authenticated user without that permission to enumerate remote cluster co...
CVE-2026-10103 Authenticated remote cluster can modify or delete posts it does not own in Mattermost Connected Workspaces shared channels
Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to verify post ownership in the shared channel inbound sync handler, which allows an authenticated remote cluster to modify or delete posts authored by local users or other remotes via crafted sync messages referencing...
CVE-2026-8823 User Manager can demote bot accounts to guest without bot-management permission
Mattermost versions 11.7.x = 11.7.0, 10.11.x = 10.11.17 fail to validate bot targets when demoting users to guests which allows a lower-privileged administrator to degrade arbitrary bot accounts via the standard demote-user API.. Mattermost Advisory ID: MMSA-2026-00669...
CVE-2026-5139 GitLab Plugin Allows Non-Admin Users to Modify Default Instance Configuration
Mattermost versions 11.7.x slash command.. Mattermost Advisory ID: MMSA-2026-00644...
PT-2026-42745
Name of the Vulnerable Software and Affected Versions Mattermost version 11.6.0 Mattermost version 11.5.3 Mattermost version 11.4.4 Mattermost version 10.11.14 Description Improper validation of file ownership and access control in the Boards API allows an authenticated user to access and downloa...
PT-2026-42748
Name of the Vulnerable Software and Affected Versions Mattermost version 11.6.0 Mattermost version 11.5.3 Mattermost version 11.4.4 Mattermost version 10.11.14 Description Insufficient input validation in the GitHub plugin API request handlers allows an authenticated attacker to cause a denial of...
CVE-2026-6333 SSRF via Host Header Spoofing in Custom Slash Commands
Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which allows an authenticated attacker to redirect slash command responses to an attacker-controlled server via a spoofed Host header.. Mattermost...
CVE-2026-6345 Prevent password disclosure and force reset during Slack import
Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail prevent disclosure of created user password which allows a malicious attacker to impersonate a user via the use of some of those passwords.. Mattermost Advisory ID: MMSA-2026-00614...
EUVD-2026-30751
Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to check public/private permissions which allows members without these permissions to access public playbooks via /get.. Mattermost Advisory ID: MMSA-2026-00591...
SUSE CVE-2026-26233
Mattermost versions 11.4.x = 11.4.0, 11.3.x = 11.3.1, 11.2.x = 11.2.3, 10.11.x = 10.11.11 fail to rate limit login requests which allows unauthenticated remote attackers to cause denial of service server crash and restart via HTTP/2 single packet attack with 100+ parallel login requests...
EUVD-2026-12516
Mattermost versions 10.11.x = 10.11.10 Fail to invalidate cached permalink preview data when a user loses channel access which allows the user to continue viewing private channel content via previously cached permalink previews until cache reset or relogin.. Mattermost Advisory ID: MMSA-2026-0058...
EUVD-2026-12415
Mattermost versions 11.3.x = 11.3.0 fail to preserve the redacted state of burn-on-read posts during deletion which allows channel members to access unrevealed burn-on-read message contents via the WebSocket post deletion event.. Mattermost Advisory ID: MMSA-2026-00579...
CVE-2026-25783
Mattermost versions 11.3.x = 11.3.0, 11.2.x = 11.2.2, 10.11.x = 10.11.10 fail to properly validate User-Agent header tokens which allows an authenticated attacker to cause a request panic via a specially crafted User-Agent header. Mattermost Advisory ID: MMSA-2026-00586...
CVE-2026-26246 Memory Exhaustion via Malformed PSD File Upload
Mattermost versions 11.3.x = 11.3.0, 11.2.x = 11.2.2, 10.11.x = 10.11.10 fail to bound memory allocation when processing PSD image files which allows an authenticated attacker to cause server memory exhaustion and denial of service via uploading a specially crafted PSD file. Mattermost Advisory I...
Time-of-check Time-of-use (TOCTOU) Race Condition
Overview Affected versions of this package are vulnerable to Time-of-check Time-of-use TOCTOU Race Condition via a race condition in the /commonteams API endpoint. An attacker can gain unauthorized access to team names by exploiting the timing of channel membership validation during data retrieva...
PT-2026-25809
Name of the Vulnerable Software and Affected Versions Mattermost versions 10.11.0 through 10.11.10 Mattermost versions 11.2.0 through 11.2.2 Mattermost versions 11.3.0 Description The software does not correctly handle array lengths reported within messages sent via WebSockets to the calls plugin...
EUVD-2025-186557
Mattermost versions 11.0 fail to properly enforce the "Allow users to view archived channels" setting which allows regular users to access archived channel content and files via the "Open in Channel" functionality from followed threads...
EUVD-2025-29172
Malicious code in bioql PyPI...