CVE-2019-20871 is a high-severity vulnerability affecting Mattermost Server versions prior to 5.9.0, 5.8.1, 5.7.3, and 4.10.8, stemming from catastrophic backtracking within its Markdown library. This flaw allows an unauthenticated attacker to remotely trigger a denial-of-service condition with low attack complexity. While no public exploit intelligence or active exploitation has been observed, and community discussion is minimal, organizations using affected Mattermost versions should prioritize patching to mitigate the risk.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
< 4.10.8CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | ||
>= 5.7.0, < 5.7.3CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | ||
>= 5.8.0, < 5.8.1CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | ||
5.9.0CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:5.9.0:rc1:*:*:*:*:*:* | ||
5.9.0CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:5.9.0:rc2:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.
Remediation records are not available for this CVE.