| Summary | Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.2, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate the TIFF IFD offset in the image header before allocating memory, which allows authenticated users with file upload or posting permissions to cause a denial of service (server OOM) via uploading a crafted TIFF file or posting a URL that serves one.. Mattermost Advisory ID: MMSA-2026-00648 |
|---|---|
| Publication Date | May 22, 2026, 8:16 p.m. |
| Registration Date | May 27, 2026, 4:05 a.m. |
| Last Update | May 23, 2026, 1:52 a.m. |
| CVSS3.1 : MEDIUM | |
| スコア | 6.5 |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:L/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) | 低 |
| 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 |
| 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 | 11.5.3 | |||
| cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | 11.6.0 | 11.6.1 | |||