Mattermost versions 11.4.0 and earlier, 11.3.1 and earlier, 11.2.3 and earlier, and 10.11.11 and earlier are affected by CVE-2026-20719, a denial-of-service vulnerability. This flaw allows unauthenticated attackers to crash the Mattermost web and desktop applications by embedding malicious external SVGs in link previews. With a CVSS score of 7.5 (High), it presents a significant availability risk due to its low attack complexity and lack of required user interaction. There is currently no evidence of active exploitation, nor is public exploit code available. Community discussion remains minimal.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 10.11.0, <= 10.11.11CPE match | cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:* | ||
>= 11.2.0, <= 11.2.3CPE match | cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:* | ||
>= 11.3.0, <= 11.3.1CPE match | cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:* | ||
>= 11.4.0, <= 11.4.0CPE match | cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:* | ||
>= 10.11.0, < 10.11.12CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.