CVE-2025-21088

Mattermost versions 10.2.x <= 10.2.0, 9.11.x <= 9.11.5, 10.0.x <= 10.0.3, 10.1.x <= 10.1.3 fail to properly validate the style of proto supplied to an action's style in post.props.attachments, which allows an attacker to crash the frontend via crafted malicious input.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
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
CISA-ADPADP
---
---
Base Score
CVSS 3.x
EPSS Score
Percentile: 43%
VendorProductVersion
mattermostmattermost_server
9.11.0 ≤
𝑥
< 9.11.6
mattermostmattermost_server
10.0.0 ≤
𝑥
< 10.0.4
mattermostmattermost_server
10.1.0 ≤
𝑥
< 10.1.4
mattermostmattermost_server
10.2.0
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://mattermost.com/security-updates