CVE-2026-95666

CVE-2026-95666 affects Mattermost versions 11.9.x ≤ 11.9.1 , 11.8.x ≤ 11.8.5 , 11.7.x ≤ 11.7.10 , and 11.10.x ≤ 11.10.1 . The bulk reactions endpoint (POST /api/v4/posts/ids/reactions) fails to limit the length of the post ID array it accepts, allowing an authenticated user to cause excessive dat...

CVE-2025-25279

Security Advisory MMSA-2025-00430 / CVE-2025-25279 Summary After uploading a file to Mattermost Boards, when the fileId parameter is modified and the board is copied, the file now points to and downloads the target file specified in the parameter. Affected Versions: Mattermost instances with Boar...

CVE-2025-25279-Mattermost-Path-Traversal

🔥 CVE-2025-25279 — Mattermost 10.4.1 📤 Path Traversal in Focalboard allowing file exfiltration 🌟 Presentation This proof of concept demonstrates the exploitation of vulnerability CVE-2025-25279 affecting Mattermost 10.4.1. A flaw in Focalboard the board management module allows arbitrary file...

dr_robot

root@kitploit: . . . . . . . : \ : \ : \ : . \ : / : . \ \ :| | | || || || : | || | \ | : | | | :| | . | || : \ | : \ | : || | | : | | | |. / | || |\ . / |/ . / | | :/ || || :/ :/ || : : : Copyright 2019 National Technology & Engineering Solutions of Sandia, LLC NTESS. Under the terms of...

CVE-2026-75588

Mattermost Desktop App versions =6.2 6.2.2.0 fail to validate the URL scheme when checking whether a target URL is internal to the connected server, which allows a network-positioned attacker to load a plugin popout window over an insecure connection via a link using a downgraded URL scheme...

CVE-2026-12284

Mattermost Desktop App versions =6.2 6.2.2.0 fails to validate the IPC sender in the leaveCall handler which allows a malicious or compromised Mattermost server or a user with script access to a connected server view to disconnect an active call belonging to a different connected server via the...

CVE-2026-12284

Mattermost Desktop App versions

EUVD-2026-81680

Mattermost Desktop App versions =6.2 6.2.2.0 fails to validate the IPC sender in the leaveCall handler which allows a malicious or compromised Mattermost server or a user with script access to a connected server view to disconnect an active call belonging to a different connected server via the...

EUVD-2026-81678

Mattermost Desktop App versions =6.2 6.2.2.0 fail to validate the URL scheme when checking whether a target URL is internal to the connected server, which allows a network-positioned attacker to load a plugin popout window over an insecure connection via a link using a downgraded URL scheme...

CVE-2026-75588

Mattermost Desktop App versions

CVE-2026-75025

Mattermost Desktop App versions =6.2 6.2.2.0 Fixed an issue where Mattermost Desktop did not sufficiently restrict server-rendered content from accessing local or private network resources. Thanks to game0v3r for contributing to this improvement under the Mattermost responsible disclosure policy...

EUVD-2026-80939

Mattermost Desktop App versions =6.2 6.2.2.0 Fixed an issue where Mattermost Desktop did not sufficiently restrict server-rendered content from accessing local or private network resources. Thanks to game0v3r for contributing to this improvement under the Mattermost responsible disclosure policy...

CVE-2026-75025 Mattermost Desktop local network access from server-rendered content

Mattermost Desktop App versions =6.2 6.2.2.0 Fixed an issue where Mattermost Desktop did not sufficiently restrict server-rendered content from accessing local or private network resources. Thanks to game0v3r for contributing to this improvement under the Mattermost responsible disclosure policy...

CVE-2026-75025

Mattermost Desktop App versions up to and including 6.2 are affected by a restriction flaw: server-rendered content was not sufficiently restricted from accessing local or private network resources from the desktop client. The issue was rated CVSS 3.1: 4.7 (MEDIUM) with a changed scope and low co...

EUVD-2026-78160

Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7, 10.11.x = 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret...

CVE-2026-91181

Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7, 10.11.x = 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret...

CVE-2026-91181 Data Retention Teams Endpoint Leaks Private Team Invite ID

Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7, 10.11.x = 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret...

CVE-2026-91181

CVE-2026-91181 affects Mattermost versions 11.9.0 and earlier, 11.8.4 and earlier, 11.7.7 and earlier, and 10.11.22 and earlier. The data retention teams endpoint (GET /api/v4/data_retention/policies/{policy_id}/teams) fails to sanitize Team objects, allowing an authenticated user with only the r...

CVE-2026-12985

Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7 Mattermost failed to validate Dynamic Client Registration redirect URIs by URL component matching glob patterns against the raw URI string instead which allows a remote unauthenticated attacker to register an OAuth client with ...

CVE-2026-86348

Mattermost versions =11.9 11.0.9 11.4.8 11.7.7 10.22.11.0 fail to recover from handler panics, which allows an authenticated user to crash the plugin via a post-action request with an unexpected field type.. Mattermost Advisory ID: MMSA-2026-00701...