CVE-2026-7521

Mattermost versions 11.8.x = 11.8.0, 11.7.x = 11.7.3, 11.6.x = 11.6.5, 10.11.x = 10.11.20 fail to verify file deletion path which allows an admin with SAML system-console write permissions to delete arbitrary files outside the config directory from the server via the remove file endpoint...

CVE-2026-7521

Mattermost versions 11.8.x = 11.8.0, 11.7.x = 11.7.3, 11.6.x = 11.6.5, 10.11.x = 10.11.20 fail to verify file deletion path which allows an admin with SAML system-console write permissions to delete arbitrary files outside the config directory from the server via the remove file endpoint...

CVE-2026-7521

Mattermost CVE-2026-7521 affects versions 11.8.x up to 11.8.0, 11.7.x up to 11.7.3, 11.6.x up to 11.6.5, and 10.11.x up to 10.11.20. The issue arises from a failure to verify the file deletion path in the remove file endpoint for SAML admin writes, enabling deletion of arbitrary files outside the...

EUVD-2026-49852

Mattermost versions 11.8.x = 11.8.0, 11.7.x = 11.7.3, 11.6.x = 11.6.5, 10.11.x = 10.11.20 fail to verify file deletion path which allows an admin with SAML system-console write permissions to delete arbitrary files outside the config directory from the server via the remove file endpoint...

CVE-2026-7521 SAML certificate deletion allows path traversal to delete arbitrary files outside the config directory

Mattermost versions 11.8.x = 11.8.0, 11.7.x = 11.7.3, 11.6.x = 11.6.5, 10.11.x = 10.11.20 fail to verify file deletion path which allows an admin with SAML system-console write permissions to delete arbitrary files outside the config directory from the server via the remove file endpoint...

CVE-2026-10819

Mattermost versions 11.6.x = 11.6.5, 10.11.x = 10.11.20, 11.8.x = 11.8.1, 11.7.x = 11.7.4 fail to limit the number of frames and enforce the file size cap on animated GIF uploads, which allows an authenticated attacker to cause a denial of service via a crafted animated GIF uploaded as a custom...

CVE-2026-10600

Mattermost versions 11.8.x = 11.8.0, 11.7.x = 11.7.3, 11.6.x = 11.6.5, 10.11.x = 10.11.20 fail to bound the time and resource consumption of server-side document content extraction which allows an authenticated user with file-upload permission to degrade file uploads for all users on the server v...

EUVD-2026-49254

Mattermost versions 11.6.x = 11.6.5, 10.11.x = 10.11.20, 11.8.x = 11.8.1, 11.7.x = 11.7.4 fail to limit the number of frames and enforce the file size cap on animated GIF uploads, which allows an authenticated attacker to cause a denial of service via a crafted animated GIF uploaded as a custom...

CVE-2026-10819 Mattermost Server Denial of Service via Animated GIF Emoji Upload

Mattermost versions 11.6.x = 11.6.5, 10.11.x = 10.11.20, 11.8.x = 11.8.1, 11.7.x = 11.7.4 fail to limit the number of frames and enforce the file size cap on animated GIF uploads, which allows an authenticated attacker to cause a denial of service via a crafted animated GIF uploaded as a custom...

CVE-2026-10819

The CVE CVE-2026-10819 affects Mattermost server versions 11.6.x <= 11.6.5, 10.11.x <= 10.11.20, 11.8.x <= 11.8.1, and 11.7.x

CVE-2026-10600

Mattermost versions 11.8.x = 11.8.0, 11.7.x = 11.7.3, 11.6.x = 11.6.5, 10.11.x = 10.11.20 fail to bound the time and resource consumption of server-side document content extraction which allows an authenticated user with file-upload permission to degrade file uploads for all users on the server v...

EUVD-2026-49253

Mattermost versions 11.8.x = 11.8.0, 11.7.x = 11.7.3, 11.6.x = 11.6.5, 10.11.x = 10.11.20 fail to bound the time and resource consumption of server-side document content extraction which allows an authenticated user with file-upload permission to degrade file uploads for all users on the server v...

CVE-2026-10600 Denial of service via unbounded document content extraction in Mattermost Server

Mattermost versions 11.8.x = 11.8.0, 11.7.x = 11.7.3, 11.6.x = 11.6.5, 10.11.x = 10.11.20 fail to bound the time and resource consumption of server-side document content extraction which allows an authenticated user with file-upload permission to degrade file uploads for all users on the server v...

CVE-2026-10600

Mattermost Server vulnerability CVE-2026-10600 affects multiple release lines (Mattermost 11.8.x up to 11.8.0, 11.7.x up to 11.7.3, 11.6.x up to 11.6.5, 10.11.x up to 10.11.20). An authenticated user with file-upload permission can trigger unbounded server-side document content extraction, failin...

CVE-2026-9602

Mattermost Desktop App versions =6.2 6.0.2 5.6.13.0 fail to validate payloads sent from the Mattermost Web App to the Desktop App which allows a malicious server owner to crash the Mattermost Desktop App via changing the payload of a method to a malformed one. Mattermost Advisory ID: MMSA-2026-00...

CVE-2026-8075

Mattermost Desktop App versions =6.2 5.5.13 6.0.2.0 fail to properly null check when checking for headers in the Mattermost Desktop App which allows any user to crash another channel members Desktop App via posting a malicious link with an embedded image that misses one of those headers. Mattermo...

EUVD-2026-45157

Mattermost Desktop App versions =6.2 5.5.13 6.0.2.0 fail to properly null check when checking for headers in the Mattermost Desktop App which allows any user to crash another channel members Desktop App via posting a malicious link with an embedded image that misses one of those headers. Mattermo...

CVE-2026-8075

Mattermost Desktop App versions =6.2 5.5.13 6.0.2.0 fail to properly null check when checking for headers in the Mattermost Desktop App which allows any user to crash another channel members Desktop App via posting a malicious link with an embedded image that misses one of those headers. Mattermo...

CVE-2026-8075 Posting a malicious markdown image crashes the Mattermost Desktop App

Mattermost Desktop App versions =6.2 5.5.13 6.0.2.0 fail to properly null check when checking for headers in the Mattermost Desktop App which allows any user to crash another channel members Desktop App via posting a malicious link with an embedded image that misses one of those headers. Mattermo...

CVE-2026-8075 Posting a malicious markdown image crashes the Mattermost Desktop App

Mattermost Desktop App versions =6.2 5.5.13 6.0.2.0 fail to properly null check when checking for headers in the Mattermost Desktop App which allows any user to crash another channel members Desktop App via posting a malicious link with an embedded image that misses one of those headers. Mattermo...