CVE-2026-5740
| Summary |
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 properly validate msgpack-encoded WebSocket frames before memory allocation which allows an unauthenticated remote attacker to crash the server process and cause a full service outage for all users via a crafted binary WebSocket message sent to the public WebSocket endpoint.. Mattermost Advisory ID: MMSA-2026-00647
|
| Publication Date |
May 22, 2026, 8:16 p.m. |
| Registration Date |
May 27, 2026, 4:05 a.m. |
| Last Update |
May 23, 2026, 1:53 a.m. |
|
CVSS3.1 : HIGH
|
| スコア |
7.5
|
| Vector |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 攻撃元区分(AV) |
ネットワーク |
| 攻撃条件の複雑さ(AC) |
低 |
| 攻撃に必要な特権レベル(PR) |
不要 |
| 利用者の関与(UI) |
不要 |
| 影響の想定範囲(S) |
変更なし |
| 機密性への影響(C) |
なし |
| 完全性への影響(I) |
なし |
| 可用性への影響(A) |
高 |
Affected software configurations
| Configuration1 |
or higher |
or less |
more than |
less than |
| cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* |
10.11.0 |
|
|
10.11.15 |
| cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* |
11.4.0 |
|
|
11.4.5 |
| cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* |
11.5.0 |
|
|
11.5.4 |
| cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* |
11.6.0 |
|
|
11.6.1 |
Related information, measures and tools
Common Vulnerabilities List