Cyber Resilience

CVE-2025-21088

Medium

Published: 15 January 2025

Published
15 January 2025
Modified
30 September 2025
KEV Added
Patch
CVSS Score v3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0025 48.2th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-21088 is a medium-severity Incorrect Type Conversion or Cast (CWE-704) vulnerability in Mattermost Mattermost Server. Its CVSS base score is 6.5 (Medium).

Operationally, ranked at the 48.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

input.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

mattermost
mattermost server
10.2.0 · 9.11.0 — 9.11.6 · 10.0.0 — 10.0.4 · 10.1.0 — 10.1.4

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References