CVE-2026-14259

EUVD-2026-77359
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to enforce board creation permissions when importing archive files which allows an authenticated non-guest team member to create Open or Private boards despite administrator restrictions via importing a crafted .boardarchive file. Mattermost Advisory ID: MMSA-2026-00712
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
MattermostCNA
4.3 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
𝑥
≤ 11.9.0
CNA
mattermostmattermost
11.8.0 ≤
𝑥
≤ 11.8.4
CNA
mattermostmattermost
11.7.0 ≤
𝑥
≤ 11.7.7
CNA
mattermostmattermost
10.11.0 ≤
𝑥
≤ 10.11.22
CNA
Common Weakness Enumeration
References
https://mattermost.com/security-updates