Search vulnerabilities

Use the Query Builder to create your own search query, or check out the documentation to learn the search syntax.

Results 8

Export CSV
CVE-2026-2456

Denial of Service via Unbounded Memory Allocation in Integration Actions

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 Mattermost fails to limit the size of responses from integration action endpoints, which allows an authenticated attacker to cause server memory exhaustion and denial of service via a malicious integration server that returns an arbitrarily large response when a user clicks an interactive message button.. Mattermost Advisory ID: MMSA-2026-00571

CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
Vendors
Mattermost
Products
Mattermost Mattermost Server Server
CVE-2026-2463

Unauthorized access to invite ID during team creation

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to filter invite IDs based on user permissions, which allows regular users to bypass access control restrictions and register unauthorized accounts via leaked invite IDs during team creation.. Mattermost Advisory ID: MMSA-2025-00565

CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Vendors
Mattermost
Products
Mattermost Mattermost Server Server
CVE-2026-2458

Unauthorized channel enumeration in private teams after member removal

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate team membership when searching channels which allows a removed team member to enumerate all public channels within a private team via the channel search API endpoint.. Mattermost Advisory ID: MMSA-2025-00568

CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Vendors
Mattermost
Products
Mattermost Server Server
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 ID: MMSA-2026-00572

CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Vendors
Mattermost
Products
Mattermost Mattermost Server Server
CVE-2026-2578

Information Disclosure via WebSocket Event When Deleting Unrevealed Burn on Read Posts

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

CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Vendors
Mattermost
Products
Mattermost Server Server
CVE-2026-2462

Admin RCE via Malicious Plugin Upload on CI Test Instances

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to restrict plugin installation on CI test instances with default admin credentials which allows an unauthenticated attacker to achieve remote code execution and exfiltrate sensitive configuration data including AWS and SMTP credentials via uploading a malicious plugin after changing the import directory. Mattermost Advisory ID: MMSA-2025-00528

CVSS 3.1 · 6.6 Medium EPSS < 1% KEV · Not listed
Vendors
Mattermost
Products
Mattermost Server Server
CVE-2026-4265

Guest user can upload files without permission across teams

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to validate team-specific upload_file permissions which allows a guest user to post files in channels where they lack upload_file permission via uploading files in a team where they have permission and reusing the file metadata in a POST request to a different team. Mattermost Advisory ID: MMSA-2025-00553

CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Vendors
Mattermost
Products
Mattermost Mattermost Server Server
CVE-2025-47700

AI plugin APIs can be triggered using post actions

Mattermost Server versions 10.5.x <= 10.5.9 utilizing the Agents plugin fail to reject empty request bodies which allows users to trick users into clicking malicious links via post actions

CVSS 3.1 · 3.5 Low EPSS < 1% KEV · Not listed
Vendors
Mattermost
Products
Mattermost Mattermost Server Server