CVEvulnerability
CVE-2026-19603
4.3 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2026-10-16
- Last modified
- 2026-10-29
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 4.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- Weaknesses
- CWE-201
Description
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to sanitize the active channel field returned by the user status API endpoints, which allows an authenticated user to learn the channel ID of a private channel another user is actively viewing via the status endpoints, without being a member of that channel. Mattermost Advisory ID: MMSA-2026-00765
Affected configurations
• mattermost mattermost server (>= 11.7.0 < 11.7.11)
• mattermost mattermost server (>= 11.8.0 < 11.8.6)
• mattermost mattermost server (>= 11.9.0 < 11.9.2)
• mattermost mattermost server (>= 11.10.0 < 11.10.2)
Related
Weakness · CWE (1)
- CWE-201 Insertion of Sensitive Information Into Sent Data weakness
References
- https://mattermost.com/security-updates Vendor Advisory