Description
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to validate the length and content of message attachment field values, which allows an authenticated attacker to cause a denial of service for all users in a channel via a post containing a specially crafted payload that triggers catastrophic backtracking in the client-side markdown parser.. Mattermost Advisory ID: MMSA-2026-00658
CVSS 6.5EPSS 0.24%Risk 0.66
View source- Published
- 2026-07-13 09:16:24
- Affected versions
- <= 11.7.2, <= 11.6.4, <= 10.11.19
- Type
- Web application
- Vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H