CVE-2023-4478

8.2 highEPSS 0.5%

High (8.2) in mattermost mattermost server. EPSS 0.5% chance of exploitation in the next 30 days.

Mattermost fails to restrict which parameters' values it takes from the request during signup allowing an attacker to register users as inactive, thus blocking them from later accessing Mattermost without the system admin activating their accounts.

Severity

CVSS 3.1

8.2 high

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

EPSS: 0.5% chance of exploitation in the next 30 days; higher than 43% of CVEs (scores of 2026-10-31)
CWE: CWE-74
Published: 2023-08-25
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

mattermost:mattermost_server

References

https://mattermost.com/security-updates
https://mattermost.com/security-updates

Check your stack JSON