Persistent notification timing attack causing server denial of service
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
Problem Types
| Type | CWE ID | Description |
|---|
| CWE | CWE-362 | CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') |
Type: CWE
Description: CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Metrics
| Version | Base score | Base severity | Vector |
|---|
| 3.1 | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Version: 3.1
Base score: 6.5
Base severity: MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H