CVE-2026-16453

Mattermost versions 11.10.x = 11.10.0, 11.7.x = 11.7.9, 11.9.x = 11.9.1, 11.8.x = 11.8.5 fail to verify the integrity of the SAML RelayState POST parameter which allows an authenticated SAML user to join any team, including invite-only teams, via forging the teamid or inviteid fields in the...

EUVD-2026-102745

Mattermost versions 11.10.x = 11.10.0, 11.7.x = 11.7.9, 11.9.x = 11.9.1, 11.8.x = 11.8.5 fail to verify the integrity of the SAML RelayState POST parameter which allows an authenticated SAML user to join any team, including invite-only teams, via forging the teamid or inviteid fields in the...

CVE-2026-16453

Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, and 11.8.x

CVE-2026-16453: External Control of Assumed-Immutable Web Parameter

Mattermost versions 11.10.x = 11.10.0, 11.7.x = 11.7.9, 11.9.x = 11.9.1, 11.8.x = 11.8.5 fail to verify the integrity of the SAML RelayState POST parameter which allows an authenticated SAML user to join any team, including invite-only teams, via forging the teamid or inviteid fields in the...

Mattermost Server 10.11.x < 10.11.23 / 11.7.x < 11.7.8 / 11.8.x < 11.8.5 / 11.9.x < 11.9.1 Incorrect Authorization (MMSA-2026-00702)

The version of Mattermost Server installed on the remote host is affected by a vulnerability as referenced in the MMSA-2026-00702 advisory. - Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7, 10.11.x = 10.11.22 fail to sanitize Team objects returned by the data retention team...

EUVD-2026-78160

Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7, 10.11.x = 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret...

CVE-2026-91181

Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7, 10.11.x = 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret...

CVE-2026-91181 Data Retention Teams Endpoint Leaks Private Team Invite ID

Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7, 10.11.x = 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret...

CVE-2026-91181

CVE-2026-91181 affects Mattermost versions 11.9.0 and earlier, 11.8.4 and earlier, 11.7.7 and earlier, and 10.11.22 and earlier. The data retention teams endpoint (GET /api/v4/data_retention/policies/{policy_id}/teams) fails to sanitize Team objects, allowing an authenticated user with only the r...

CVE-2026-91181: Incorrect Authorization

Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7, 10.11.x = 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret...

CVE-2018-21261

An issue was discovered in Mattermost Server before 4.8.1, 4.7.4, and 4.6.3. An e-mail invite accidentally included the team inviteid, which leads to unintended excessive invitation privileges...

CVE-2018-21261: Incorrect Permission Assignment for Critical Resource

An issue was discovered in Mattermost Server before 4.8.1, 4.7.4, and 4.6.3. An e-mail invite accidentally included the team inviteid, which leads to unintended excessive invitation privileges...