Mattermost versions 10.11.x <= 10.11.18, 11.6.x <= 11.6.3, 11.5.x <= 11.5.6 fail to properly apply markdown image rendering restrictions to AI bot tool result posts, which allows an authenticated attacker to exfiltrate data to an attacker-controlled server via injecting markdown image syntax into tool result content rendered by a victim's client.. Mattermost Advisory ID: MMSA-2026-00619
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 10.11.0, < 10.11.19CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | ||
>= 11.5.0, < 11.5.7CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | ||
>= 11.6.0, < 11.6.4CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | ||
>= 10.11.0, <= 10.11.18CPE match | cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:* | ||
>= 11.5.0, <= 11.5.6CPE 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:R/S:U/C:L/I:N/A:N
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.2 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.