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PatchSiren cyber security CVE debrief

CVE-2016-20026 ZKTeco Inc. CVE debrief

CVE-2016-20026 is a critical vulnerability in ZKTeco ZKBioSecurity 3.0. The vulnerability exists due to hardcoded credentials in the bundled Apache Tomcat server, allowing unauthenticated attackers to access the manager application. Attackers can authenticate with these hardcoded credentials, stored in tomcat-users.xml, to upload malicious WAR archives containing JSP applications and execute arbitrary code with SYSTEM privileges.

Vendor
ZKTeco Inc.
Product
ZKTeco ZKBioSecurity
CVSS
CRITICAL 9.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-03-16
Original CVE updated
2026-06-08
Advisory published
2026-03-16
Advisory updated
2026-06-08

Who should care

Administrators and users of ZKTeco ZKBioSecurity 3.0 should be aware of this vulnerability and take necessary actions to mitigate the risk.

Technical summary

The vulnerability has a CVSS score of 9.3 and is classified as CRITICAL. It allows attackers to execute arbitrary code with SYSTEM privileges.

Defensive priority

High

Recommended defensive actions

  • Update ZKTeco ZKBioSecurity 3.0 to a version that does not contain hardcoded credentials.
  • Change the default credentials of the Apache Tomcat server.
  • Restrict access to the manager application.

Evidence notes

The vulnerability was reported by an unknown vendor and has a low confidence level.

Sources and references

Verified primary and authoritative sources

  • CVE-2016-20026 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2016-20026

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2016-20026 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2016-20026

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.