CVE-2025-20621

MEDIUM

Mattermost <10.2.0-10.2.0, <9.11.5-9.11.5, <10.0.3-10.0.3, <10.1.3-...

Title source: llm

Description

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 handle posts with attachments containing fields that cannot be cast to a String, which allows an attacker to cause the webapp to crash via creating and sending such a post to a channel.

References (1)

[Vendor Advisory] https://mattermost.com/security-updates

Scores

CVSS v3 6.5

EPSS 0.0039

EPSS Percentile 60.0%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-1287

Status published

Products (3)

mattermost/mattermost 10.2.0 - 10.2.1Go

mattermost/mattermost_server 10.2.0

mattermost/mattermost_server 9.11.0 - 9.11.6

Published Jan 16, 2025

Tracked Since Feb 18, 2026