CVE-2026-6340 — Memory Exhaustion via Malicious 7zip File Upload

CVE-2026-6340

Memory Exhaustion via Malicious 7zip File Upload PUBLISHED

Description (CNA)

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 (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.5.0 through 11.5.1; affected 10.11.0 through 10.11.13; affected 11.4.0 through 11.4.3; unaffected 11.6.0; unaffected 11.5.2; unaffected 10.11.14; unaffected 11.4.4

CWE

CWE-789

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.