VULNERABILITY INTELLIGENCE

CVE-2026-6340

CVSS score4.3 MEDIUM
EPSS probability0.24%
CISA KEVNot currently listed
Published2026-05-18
Last modified2026-10-14
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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

Weakness classification

  • CWE-789: Memory Allocation with Excessive Size Value

Primary references