GO-2026-5442 Mattermost doesn't enforce the PostEditTimeLimit on non-message post fields in github.com/mattermost/mattermost-server

Mattermost doesn't enforce the PostEditTimeLimit on non-message post fields in github.com/mattermost/mattermost-server...

GO-2026-5484 Mattermost doesn't escape some variables that could contain malicious content during error page composition in github.com/mattermost/mattermost-server

Mattermost doesn't escape some variables that could contain malicious content during error page composition in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. If...

GO-2026-5507 Mattermost has session spoofing due to lack of single-use consumption of guest magic link tokens enforcement in github.com/mattermost/mattermost-server

Mattermost has session spoofing due to lack of single-use consumption of guest magic link tokens enforcement in github.com/mattermost/mattermost-server...

GO-2026-5495 Mattermost doesn't validate CSRF tokens on an authentication endpoint in github.com/mattermost/mattermost-server

Mattermost doesn't validate CSRF tokens on an authentication endpoint in github.com/mattermost/mattermost-server...

GO-2026-5311 Mattermost has a Path Traversal issue in github.com/mattermost/mattermost-server

Mattermost has a Path Traversal issue in github.com/mattermost/mattermost-server...

GO-2026-5325 Mattermost doesn't validate 7zip archive structure before processing in github.com/mattermost/mattermost-server

Mattermost doesn't validate 7zip archive structure before processing in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. If this is causing false-positive reports...

GO-2026-5393 Mattermost has an Incorrect Authorization issue in github.com/mattermost/mattermost-server

Mattermost has an Incorrect Authorization issue in github.com/mattermost/mattermost-server...

GO-2026-5293 Mattermost doesn't sanitize sensitive configuration fields before including them in support packet generation in github.com/mattermost/mattermost-server

Mattermost doesn't sanitize sensitive configuration fields before including them in support packet generation in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. I...

GO-2026-5360 Mattermost allows attackers to take over arbitrary user accounts via overly permissive substring matching flaw in github.com/mattermost/mattermost-server

Mattermost allows attackers to take over arbitrary user accounts via overly permissive substring matching flaw in github.com/mattermost/mattermost-server...

GO-2026-5263 Mattermost doesn't verify channel membership when processing AI-assisted message rewrites in github.com/mattermost/mattermost-server

Mattermost doesn't verify channel membership when processing AI-assisted message rewrites in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. If this is causing...

GO-2026-5256 Mattermost does not verify remote cluster channel access when processing shared channel membership removals in github.com/mattermost/mattermost-server

Mattermost does not verify remote cluster channel access when processing shared channel membership removals in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. If...

GO-2026-5245 Mattermost: Authenticated DoS through failure to prevent rendering of external SVGs on link embeds in github.com/mattermost/mattermost-server

Mattermost: Authenticated DoS through failure to prevent rendering of external SVGs on link embeds in github.com/mattermost/mattermost-server...

GO-2026-5112 Mattermost doesn't set permissions on downloaded bulk export in github.com/mattermost/mattermost-server

Mattermost doesn't set permissions on downloaded bulk export in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. If this is causing false-positive reports from...

GO-2026-5173 Mattermost has an Incorrect Authorization issue in github.com/mattermost/mattermost-server

Mattermost has an Incorrect Authorization issue in github.com/mattermost/mattermost-server...

GO-2026-5067 Mattermost allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences in github.com/mattermost/mattermost-server

Mattermost allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences in github.com/mattermost/mattermost-server...

Mattermost Server 10.11.x < 10.11.14 / 11.5.x < 11.5.2 Vulnerability (MMSA-2025-00552)

The version of Mattermost Server installed on the remote host is affected by a vulnerability: - Mattermost fails to check if teamid was being changed when updating playbooks, allowing users with only Manage Playbook Configurations permission to change a playbook's team, bypassing manage members...

Mattermost Server 10.11.x < 10.11.14 / 11.4.x < 11.4.4 / 11.5.x < 11.5.2 Vulnerability (MMSA-2026-00597)

The version of Mattermost Server installed on the remote host is affected by a vulnerability: - Mattermost fails to enforce slash command trigger-word uniqueness during command updates which allows an authenticated team member with Manage Own Slash Commands permission to hijack and impersonate...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization via the schemeadmin flag in group syncable link and patch endpoints. An attacker can gain unauthorized administrative privileges by sending crafted API requests. Remediation Upgrade...

CVE-2026-6046 Plugin bot username conflict allows user account to be used as bot identity in Mattermost Server

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15, 10.11.x = 10.11.16 fail to validate that a username returned during bot registration belongs to a bot account, which allows an unprivileged attacker to intercept private messages sent by plugins via direct message channels ...

CVE-2026-4635

Mattermost versions 11.6.x = 11.6.0, 11.5.x = 11.5.3, 11.4.x = 11.4.4, 10.11.x = 10.11.14 fail to archive the channel before removing persistent notifications which allows authenticated user to crash the server via timing the creation of persistent notification message between the server deleting...