Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to verify post ownership in the shared channel inbound sync handler, which allows an authenticated remote cluster to modify or delete posts authored by local users or other remotes via crafted sync messages referencing arbitrary post IDs in channels shared with that remote.. Mattermost Advisory ID: MMSA-2026-00689
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 10.11.0, < 10.11.20CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | ||
>= 11.6.0, < 11.6.5CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | ||
>= 11.7.0, < 11.7.3CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | ||
>= 10.11.0, <= 10.11.19CPE match | cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:* | ||
>= 11.6.0, <= 11.6.4CPE match | cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.
Remediation records are not available for this CVE.