SUSE CVE-2026-25780

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 DOC files which allows an authenticated attacker to cause server memory exhaustion and denial of service via uploading a specially crafted DOC file.. Mattermost Advisory ID:...

SUSE 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...

SUSE CVE-2026-26246

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...

SUSE CVE-2026-26304

Mattermost versions 11.3.x = 11.3.0, 11.2.x = 11.2.2 fail to verify runcreate permission for empty playbookId, which allows team members to create unauthorized runs via the playbook run API. Mattermost Advisory ID: MMSA-2025-00542...

CVE-2026-3109

Mattermost Plugins versions =11.4 10.11.11.0 fail to validate webhook request timestamps which allows an attacker to corrupt Zoom meeting state in Mattermost via replayed webhook requests. Mattermost Advisory ID: MMSA-2026-00584...

Incorrect Authorization

Overview @openclaw/mattermost is an OpenClaw Mattermost channel plugin Affected versions of this package are vulnerable to Incorrect Authorization in the auth process. An attacker can gain unauthorized access by sending requests with add-on principals that are not bound to the intended deployment...

GHSA-8883-9W57-VWV6 OpenClaw: Mattermost callback dispatch allowed non-allowlisted sender actions

Summary Mattermost interactive callback dispatch could run action handlers before normal sender authorization checks completed. Affected Packages / Versions - Package: openclaw npm - Affected: = 2026.3.22 - Latest released tag checked: v2026.3.23-2 630f1479c44f78484dfa21bb407cbe6f171dac87 - Lates...

Incorrect Authorization

Overview @openclaw/mattermost is an OpenClaw Mattermost channel plugin Affected versions of this package are vulnerable to Incorrect Authorization via the callback process. An attacker can execute unauthorized actions by sending specially crafted requests before sender authorization checks are...

OpenClaw: Mattermost callback dispatch allowed non-allowlisted sender actions

Summary Mattermost interactive callback dispatch could run action handlers before normal sender authorization checks completed. Affected Packages / Versions - Package: openclaw npm - Affected: = 2026.3.22 - Latest released tag checked: v2026.3.23-2 630f1479c44f78484dfa21bb407cbe6f171dac87 - Lates...

GO-2026-4725 Mattermost fails to properly validate User-Agent header tokens in github.com/mattermost/mattermost-server

Mattermost fails to properly validate User-Agent header tokens 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-2026-4726 Mattermost fails to limit the size of responses from integration action endpoints in github.com/mattermost/mattermost-server

Mattermost fails to limit the size of responses from integration action endpoints 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...

CVE-2026-3115

A flaw was found in Mattermost. Authenticated guest users can exploit this vulnerability by retrieving group member IDs through the group retrieval endpoint. This failure to apply view restrictions allows them to enumerate user IDs that are outside their permitted visibility scope, leading to...

CVE-2026-3113

A flaw was found in Mattermost. The system fails to properly set file permissions on downloaded bulk exports. This vulnerability allows other local users on the server to read the sensitive contents of these bulk export files, leading to unauthorized information disclosure...

CVE-2026-3114

A flaw was found in Mattermost. Authenticated users with file upload permissions can exploit this vulnerability by uploading specially crafted zip archives, known as "zip bombs," which contain highly compressed entries. When these archives are decompressed, they exhaust server memory, leading to ...

CVE-2026-3112

A flaw was found in Mattermost. This vulnerability allows a system administrator to read arbitrary files on the host system. This is possible due to a failure to properly validate Advanced Logging file target paths, which can be exploited by providing a malicious AdvancedLoggingJSON configuration...

CVE-2026-3108

A flaw was found in Mattermost. This vulnerability in the mmctl command-line interface allows attackers to manipulate administrator terminals. By sending specially crafted messages containing ANSI and Operating System Command OSC escape sequences, an attacker can enable screen manipulation, displ...

Improper Neutralization

Overview Affected versions of this package are vulnerable to Improper Neutralization via the mmctl component. An attacker can execute arbitrary terminal escape sequences by sending specially crafted messages, potentially leading to manipulation of administrator terminals, including screen...

Improper Handling of Highly Compressed Data (Data Amplification)

Overview github.com/mattermost/mattermost/server/channels/app is a private-cloud Slack alternative Affected versions of this package are vulnerable to Improper Handling of Highly Compressed Data Data Amplification in the archive extraction process. An attacker can exhaust server memory by uploadi...

Incorrect Authorization

Overview github.com/mattermost/mattermost/server/channels/app is a private-cloud Slack alternative Affected versions of this package are vulnerable to Incorrect Authorization via the group retrieval endpoint. An attacker can enumerate user IDs outside their allowed visibility scope by sending...

Denial of Service (DoS)

Overview github.com/mattermost/mattermost/server/channels/app is a private-cloud Slack alternative Affected versions of this package are vulnerable to Denial of Service DoS due to insufficient validation of incoming request size in the webhook endpoint. An attacker can disrupt service availabilit...