Back to CVE records
Medium 4.3Published May 22, 2026

CVE-2026-4646Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate user-supplied input in API request handlers which allows an authenticated attacker to cr…

Updated under an hour ago ()

Does this affect you?

It affects mattermost_server. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate user-supplied input in API request handlers which allows an authenticated attacker to crash the plugin process via a crafted HTTP request to the PR details endpoint.. Mattermost Advisory ID: MMSA-2026-00638

CVSS
4.3 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Weakness (CWE)
CWE-1287
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Not given
NVD analysis
Analyzed
Record last updated
Jul 23, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
mattermost mattermost_server
mattermost:mattermost_server
from 10.11.0 before 10.11.15; from 11.4.0 before 11.4.5; from 11.5.0 before 11.5.4; from 11.6.0 before 11.6.1
NVD

References

  • vendor-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

Your cookie choices
We use essential cookies to run this site, and, only with your consent, an advertising cookie from Google to measure whether our ads lead to sign-ups and subscriptions. See our for details.