What is CVE-2016-20026?

CVE-2016-20026 is a critical-severity vulnerability in Zkteco Inc. Zkbiosecurity, classified under Use of Hard-coded Credentials. CVSS score: 9.8/10. Published 2026-03-16.

How severe is CVE-2016-20026?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Zkteco Inc. Zkbiosecurity

CVE-2016-20026

ZKTeco ZKBioSecurity 3.0 contains hardcoded credentials in the bundled Apache Tomcat server that allow unauthenticated attackers to access the manager application. Attackers can authenticate with hardcoded credentials stored in tomcat-users.xml to upload malicious WAR archives containing JSP applications and execute arbitrary code with SYSTEM privileges.

Published 2026-03-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.008 (54.2th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 54.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Zkteco Inc. Zkbiosecurity — versions 3.0.1.0_R_230

Weakness classification (CWE)

CWE-798 — Use of Hard-coded Credentials

References

Zero Science Lab Disclosure (third-party-advisory)
CXSecurity (third-party-advisory)
IBM X-Force Exchange (vdb-entry)
Packet Storm Security (exploit)
Reference (exploit)
VulnCheck Advisory: ZKTeco ZKBioSecurity 3.0 Hardcoded Credentials Remote Code Execution (third-party-advisory)

Frequently asked questions

What is CVE-2016-20026?: CVE-2016-20026 is a critical-severity vulnerability in Zkteco Inc. Zkbiosecurity, classified under Use of Hard-coded Credentials. CVSS score: 9.8/10. Published 2026-03-16.
How severe is CVE-2016-20026?: Critical severity. CVSS v3 base score is 9.8 out of 10.