Communication and Collaboration

In Discourse versions prior to 2025.12.2, 2026.1.1, and 2026.2.0 a medium severity vulnerability CVE-2026-28218 was detected. This vulnerability allows any authenticated user to execute SQL queries in the Data Explorer plugin that have no explicit group assignments, including built-in system queries, due to fail-open access control. To address this issue, users should upgrade Discourse to versions 2025.12.2, 2026.1.1, 2026.2.0 or later. For more details, visit https://nvd.nist.gov/vuln/detail/CVE-2026-28218.

In Mattermost versions 11.1.x up to and including 11.1.2, 10.11.x up to and including 10.11.9, 11.2.x up to and including 11.2.1 and Mattermost Plugin Zoom versions up to and including 1.11.0 a medium severity vulnerability CVE-2026-0997 was detected. This vulnerability allows authenticated users to modify Zoom meeting restrictions for arbitrary channels via crafted API requests due to insufficient validation of the authenticated user in the /plugins/zoom/api/v1/channel-preference endpoint. To address this issue, users should upgrade Mattermost and the Mattermost Zoom Plugin to versions 11.3.0, 11.1.3, 10.11.10 or 11.2.2. For more details, visit https://nvd.nist.gov/vuln/detail/CVE-2026-0997.

In Mattermost versions 10.11.x up to and including 10.11.9 a low severity vulnerability CVE-2025-14573 was detected. This vulnerability allows team administrators without proper invite permissions to bypass restrictions and add users to their team via crafted API requests due to improper enforcement of invite permission checks when updating team settings through the allow_open_invite field. To address this issue, users should upgrade to versions 11.3.0 or 10.11.10. For more details, visit https://nvd.nist.gov/vuln/detail/CVE-2025-14573.

In Mattermost versions 11.1.x up to and including 11.1.2, 10.11.x up to and including 10.11.9, and 11.2.x up to and including 11.2.1 a medium severity vulnerability CVE-2025-14350 was detected. This vulnerability allows authenticated users to determine the existence of teams and their URL names by posting channel shortlinks and observing the channel_mentions property in the API response due to improper validation of team membership when processing channel mentions. To address this issue, users should upgrade Mattermost to versions 11.3.0, 11.1.3, 10.11.10 or 11.2.2. For more details, visit https://nvd.nist.gov/vuln/detail/CVE-2025-14350.

In Mattermost versions 11.1.x up to and including 11.1.2, 10.11.x up to and including 10.11.9, and 11.2.x up to and including 11.2.1 a medium severity vulnerability CVE-2025-13821 was detected. This vulnerability allows authenticated users to exfiltrate sensitive information, including password hashes and MFA secrets, via profile nickname updates or email verification events due to improper sanitization of sensitive data in WebSocket messages. To address this issue, users should upgrade Mattermost to versions 11.3.0, 11.1.3, 10.11.10 or 11.2.2. For more details, visit https://nvd.nist.gov/vuln/detail/CVE-2025-13821.

In Mattermost Jira Plugin versions 11.1.x up to and including 11.1.2, 10.11.x up to and including 10.11.9 and 11.2.x up to and including 11.2.1 a medium severity vulnerability CVE-2026-22892 was detected. This vulnerability allows authenticated attackers with access to the Jira plugin to read post content and attachments from channels they do not have access to by providing the post ID to the /create-issue API endpoint due to insufficient authorization validation. To address this issue, users should upgrade Mattermost Jira Plugin to versions 11.3.0, 11.1.3, 10.11.10 or 11.2.2. For more details, visit https://nvd.nist.gov/vuln/detail/CVE-2026-22892.

In Mattermost version 10.11.x up to and including 10.11.9 a low severity vulnerability CVE-2026-20796 was detected. This vulnerability allows a deactivated user to learn team names they should not have access to via a race condition in the /common_teams API endpoint due to improper validation of channel membership at the time of data retrieval. To address this issue, users should upgrade Mattermost to versions 10.11.10 or 11.3.0. For more details, visit https://nvd.nist.gov/vuln/detail/CVE-2026-20796.

In Mattermost Desktop App versions up to and including 6.0, 6.2.0 and 5.2.13.0 a high severity vulnerability CVE-2026-1046 was detected. This vulnerability allows a malicious Mattermost server to execute arbitrary executables on a user’s system by exploiting insufficient validation of help links when a user clicks certain items in the Help menu. To address this issue, users should upgrade Mattermost Desktop App to versions 6.1.0, 6.0.3.0 or 5.13.3.0. For more details, visit https://nvd.nist.gov/vuln/detail/CVE-2026-1046.

In Mattermost versions 11.1.x up to and including 11.1.2, 10.11.x up to and including 10.11.9 and 11.2.x up to and including 11.2.1 a medium severity vulnerability CVE-2026-0999 was detected. This vulnerability allows authenticated users to bypass SSO-only login requirements via userID-based authentication due to improper validation of login method restrictions. To address this issue, users should upgrade Mattermost to versions 11.3.0, 11.1.3, 10.11.10 or 11.2.2. For more details, visit https://nvd.nist.gov/vuln/detail/CVE-2026-0999.