CVE-2026-12284 json
Mattermost Desktop App Missing IPC Sender Validation in Calls Leave Handler
published 2026-09-17 53 d ago modified 2026-10-13 27 d ago also EUVD-2026-81680
- cvss
- 3.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 5%
- public exploits
- 0
- none known
Summary
Mattermost Desktop App versions <=6.2 6.2.2.0 fails to validate the IPC sender in the leaveCall handler which allows a malicious or compromised Mattermost server (or a user with script access to a connected server view) to disconnect an active call belonging to a different connected server via the desktopAPI.leaveCall IPC message. Mattermost Advisory ID: MMSA-2026-00699
Patch / fix
- Mattermost Mattermost 6.2.3.0, 6.3.0
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 52 d ago
Exploit prediction
0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 3.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L |
Affected products
- Mattermost Mattermost
Classification
- Weakness
-
- CWE-346 Origin Validation Error
References
-
mattermost.com
/security-updates
vendor-advisory
Sources
- CVE List CVE-2026-12284
- NVD CVE-2026-12284
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