CVE-2026-3495

EUVD-2026-30742
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to escape some variables that could contain malicious content during error page composition which allows an attacker with access to edit some site configuration to execute some malicious code via injecting some JS as part of those values.. Mattermost Advisory ID: MMSA-2026-00622
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
MattermostCNA
3.8 LOW
NETWORK
LOW
HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 7%
Affected Products (NVD)
VendorProductVersion
mattermostmattermost_server
10.11.0 ≤
𝑥
< 10.11.14
mattermostmattermost_server
11.5.0 ≤
𝑥
< 11.5.2
𝑥
= Vulnerable software versions
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
11.5.0 ≤
𝑥
≤ 11.5.1
CNA
mattermostmattermost
10.11.0 ≤
𝑥
≤ 10.11.13
CNA