CVE-2026-6340

4.3 MEDIUM

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 whi...

Published: 2026-05-18 · Last updated: 2026-05-19

Severity and scoring

CVSS: 4.3 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CWE: CWE-789

Affected products

Vendor	Product
mattermost	mattermost_server

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

Source: NVD

References

[NVD]https://nvd.nist.gov/vuln/detail/CVE-2026-6340
[Vendor advisory]https://mattermost.com/security-updates

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