CVEvulnerability
CVE-2026-6340
6.5 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2026-05-18
- Last modified
- 2026-10-14
- 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:N/I:N/A:L
- CVSS 3.1 ([email protected])
- 6.5 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-789
Description
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to validate 7zip archive structure before processing which allows an authenticated attacker to cause server memory exhaustion and denial of service via uploading a specially crafted 7zip file with excessive folder declarations.. Mattermost Advisory ID: MMSA-2026-00573
Affected configurations
• mattermost mattermost server (>= 10.11.0 < 10.11.14)
• mattermost mattermost server (>= 11.4.0 < 11.4.4)
• mattermost mattermost server (>= 11.5.0 < 11.5.2)
Related
Weakness · CWE (1)
- CWE-789 Memory Allocation with Excessive Size Value weakness
References
- https://mattermost.com/security-updates Vendor Advisory