MEDIUMCVSS v3.1 4.3Vulnerability
CVE-2026-19603
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
Properties
- Severity
- MEDIUM
- Nvd fetched at
- 2026-10-20T21:14:08.448323+00:00
- Epss score
- 0.00176
- Cvss score
- 4.3
- Cvss severity
- MEDIUM
- Retrieved at
- 2026-10-21T01:24:49+00:00
- Last source
- FIRST EPSS
- Score
- 4.3
- Cvss version
- 3.1
- Cve id
- CVE-2026-19603
- Cvss vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- First seen by Signal
- 2026-10-18T13:39:03+00:00
- Vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- Published at
- 2026-10-16T07:17:12.750
- Last modified
- 2026-10-16T19:23:18.623
- Epss percentile
- 0.0676
Related Entities (1)
HAS_WEAKNESS (1)
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