CVE-2026-3114

EUVD-2026-16242
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate decompressed archive entry sizes during file extraction which allows authenticated users with file upload permissions to cause a denial of service via crafted zip archives containing highly compressed entries (zip bombs) that exhaust server memory.. Mattermost Advisory ID: MMSA-2026-00598
Data Amplification
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
6.5 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
MattermostCNA
6.5 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Affected Products (NVD)
VendorProductVersion
mattermostmattermost
𝑥
≤ 11.4.0
mattermostmattermost
11.3.0 ≤
𝑥
≤ 11.3.1
mattermostmattermost
11.2.0 ≤
𝑥
≤ 11.2.3
mattermostmattermost
10.11.0 ≤
𝑥
≤ 10.11.11
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://mattermost.com/security-updates