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CVE PROGRAM SOURCE RECORD4.3 Medium

CVE-2026-6340

Memory Exhaustion via Malicious 7zip File Upload

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 products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Mattermost Mattermost

Default version status: unaffected

  • 11.5.0 to ≤ 11.5.1affected
  • 10.11.0 to ≤ 10.11.13affected
  • 11.4.0 to ≤ 11.4.3affected
  • 11.6.0unaffected
  • 11.5.2unaffected
  • 10.11.14unaffected
  • 11.4.4unaffected

References