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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.001 (1.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 1st percentile — 1.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000
Affected products
- Ubiquiti Unifi Network Controller — versions 5.6.43, 5.6.42, 0
Weakness classification (CWE)
References
- community.ui.com/releases/Security-Advisory-Bulletin-003-003/982bbaa8-2a07-4f81… (vendor-advisory)
- www.vulncheck.com/advisories/unifi-network-controller-improper-certificate-vali… (third-party-advisory)
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.