Medium 4.3Published Oct 16, 2025

CVE-2025-41443Guest user can discover active public channels

Updated under an hour ago (Oct 27, 2026, 3:40 PM ET)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for Mattermost

Exploited in the last 30 days

Mattermost versions 10.5.x <= 10.5.12, 10.11.x <= 10.11.2 fail to properly validate guest user permissions when accessing channel information which allows guest users to discover active public channels and their metadata via the `/api/v4/teams/{team_id}/channels/ids` endpoint

CVSS: 4.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness (CWE): CWE-862
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Mattermost
NVD analysis: Modified
Record last updated: Oct 29, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Mattermost Mattermost mattermost:mattermost (from the name)	from 10.5.0 through 10.5.12; from 10.11.0 through 10.11.2; 10.12.0 not affected; 10.5.13 not affected; 10.11.3 not affected	CNA record
mattermost mattermost_server mattermost:mattermost_server	from 10.5.0 before 10.5.11; from 10.11.0 before 10.11.3	NVD

References

References

https://mattermost.com/security-updates	vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.