GitHub Advisoryadvisory · Go
GHSA-mxq2-5jpg-7474 Mattermost doesn't validate channel ownership of an existing subscription before applying edits
MEDIUM
Official page ↗
- Aliases
- CVE-2026-6062
- Ecosystem
- Go
- Packages
- github.com/mattermost/mattermost-server
- Severity
- Moderate
- CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L
- Weaknesses
- CWE-639
- Reviewed
- 2026-09-15
Affected packages
• Go github.com/mattermost/mattermost-server: >= 11.7.0, < 11.7.1 → fixed in 11.7.1
• Go github.com/mattermost/mattermost-server: >= 11.6.0, < 11.6.3 → fixed in 11.6.3
• Go github.com/mattermost/mattermost-server: >= 11.5.0, < 11.5.6 → fixed in 11.5.6
• Go github.com/mattermost/mattermost-server: >= 10.11.0, < 10.11.18 → fixed in 10.11.18
Description
Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 Fail to validate channel ownership of an existing subscription before applying edits which allows an authenticated attacker to hijack subscriptions from channels they have no access to via a crafted PUT request to the subscription edit endpoint.. Mattermost Advisory ID: MMSA-2026-00650
Related
Alias · CVE (1)
- CVE-2026-6062 Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 Fail to validate channel ownership of an… vulnerability
Weakness · CWE (1)
- CWE-639 Authorization Bypass Through User-Controlled Key weakness