CVE-2026-9597

EUVD-2026-43315
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
MattermostCNA
5.4 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 3%
Affected Products (NVD)
VendorProductVersion
mattermostmattermost_server
11.6.0 ≤
𝑥
< 11.6.5
mattermostmattermost_server
11.7.0 ≤
𝑥
< 11.7.3
𝑥
= Vulnerable software versions
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
11.7.0 ≤
𝑥
≤ 11.7.2
CNA
mattermostmattermost
11.6.0 ≤
𝑥
≤ 11.6.4
CNA