CVE-2026-4635

Published May 22, 2026

Last updated 9 days ago

Overview

Description
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to archive the channel before removing persistent notifications which allows authenticated user to crash the server via timing the creation of persistent notification message between the server deleting existing persistent notifications and archiving the channel.. Mattermost Advisory ID: MMSA-2026-00637
Source
responsibledisclosure@mattermost.com
NVD status
Analyzed
Products
mattermost_server

Risk scores

CVSS 3.1

Type
Primary
Base score
5.3
Impact score
3.6
Exploitability score
1.6
Vector string
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

responsibledisclosure@mattermost.com
CWE-362

Social media

Hype score
Not currently trending

Configurations

References

Sources include official advisories and independent security research.