CVE-2026-2457

MEDIUM

WebSocket Message Spoofing via Permalink Embed Manipulation

Title source: cna

Description

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to sanitize client-supplied post metadata which allows an authenticated attacker to spoof permalink embeds impersonating other users via crafted PUT requests to the post update API endpoint.. Mattermost Advisory ID: MMSA-2025-00569

References (1)

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

Scores

CVSS v3 4.3

EPSS 0.0002

EPSS Percentile 5.4%

Attack Vector NETWORK

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-346

Status published

Products (10)

mattermost/mattermost 0 - 8.0.0-20260123211116-9efe617be8b8Go

Mattermost/Mattermost 10.11.0 - 10.11.10

Mattermost/Mattermost 10.11.11

Mattermost/Mattermost 11.2.0 - 11.2.2

Mattermost/Mattermost 11.2.3

Mattermost/Mattermost 11.3.0

Mattermost/Mattermost 11.3.1

Mattermost/Mattermost 11.4.0

mattermost/mattermost-server 0 - 5.3.2-0.20260123211116-9efe617be8b8Go

mattermost/mattermost_server 10.11.0 - 10.11.11

Published Mar 16, 2026

Tracked Since Mar 16, 2026