Vulnerability in Ubiquiti Unifi Network Controller

CVE-2019-25652

UniFi Network Controller before version 5.10.22 and 5.11.x before 5.11.18 contains an improper certificate verification vulnerability that allows adjacent network attackers to conduct man-in-the-middle attacks by presenting a false SSL certificate during SMTP connections. Attackers can intercept SMTP traffic and obtain credentials by exploiting the insecure SSL host verification mechanism in the SMTP certificate validation process.

Vulnerability class: Improper Certificate Validation

EPSS: 0.001 (1.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-25652?
CVE-2019-25652 is a high-severity vulnerability in Ubiquiti Unifi Network Controller, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2026-03-27.
How severe is CVE-2019-25652?
High severity. CVSS v3 base score is 7.5 out of 10.