ACAS Engineer

Position Overview

We are seeking a qualified ACAS Engineer to support vulnerability management, security compliance, and continuous monitoring operations across classified government enterprise environments. The ideal candidate will possess hands-on experience administering the Defense Information Systems Agency (DISA) Assured Compliance Assessment Solution (ACAS), including Tenable Security Center and Nessus scanners, to identify, assess, validate, and report vulnerabilities across complex, segmented networks.

The ACAS Engineer will support enterprise security operations by maintaining scanning infrastructure, executing vulnerability and compliance assessments, analyzing scan results, validating findings, and providing actionable remediation guidance to system owners, information system security teams, and government leadership. This role requires a strong understanding of DISA security requirements, Risk Management Framework (RMF) processes, and classified network security operations.

Key Responsibilities

• Administer and maintain Tenable Security Center, including user access controls, repository configurations, scan zones, scanning policies, and enterprise vulnerability management operations.
• Maintain, configure, monitor, and troubleshoot distributed Nessus scanner infrastructure.
• Plan, configure, and execute network discovery, vulnerability, and compliance scans across classified and unclassified government information systems, as authorized.
• Analyze ACAS scan results to identify security weaknesses, validate findings, investigate anomalies, and resolve false positives through technical verification and documented analysis.
• Map identified vulnerabilities to applicable security requirements and provide system owners with clear, prioritized remediation recommendations, supporting evidence, and risk-based corrective actions.
• Develop and maintain vulnerability and compliance dashboards, executive summaries, and technical reports for government leadership, cybersecurity stakeholders, and laboratory security teams.
• Support ongoing security assessment activities by monitoring scan coverage, identifying assessment gaps, tracking remediation progress, and maintaining accurate vulnerability status information.
• Coordinate with cybersecurity operations, system administrators, network engineers, and information system security personnel to resolve scanning issues and improve assessment effectiveness.
• Maintain standard operating procedures, scan configurations, troubleshooting documentation, and operational metrics in accordance with contract requirements and government security policies.
• Perform all duties in accordance with applicable government security policies, classification requirements, access restrictions, and approved system operating procedures.

Required Qualifications

• Minimum of 8 years with BS/BA; Minimum of 6 years with MS/MA; Minimum of 3 years with PhD., 12 years with a HS Diploma
• Demonstrated experience administering and operating ACAS using Tenable Security Center and Nessus.
• Experience managing enterprise vulnerability scanning operations across large, distributed, and segmented network environments.
• Hands-on experience configuring scan policies, managing scan zones and repositories, maintaining scanner connectivity, and troubleshooting scan failures.
• Demonstrated ability to analyze vulnerability and compliance findings, validate results, identify false positives, and develop practical remediation recommendations.
• Experience producing vulnerability reports, compliance summaries, dashboards, and technical briefings for government customers and senior leadership.
• Understanding of the Risk Management Framework, continuous monitoring, vulnerability remediation tracking, and security authorization processes.
• Ability to communicate technical findings clearly to system administrators, security personnel, program stakeholders, and government leadership.
• Ability to work independently and collaboratively in a mission-focused, security-conscious government contracting environment.
• US Citizen with Department of Energy clearance

Preferred Qualifications

• Experience supporting Department of Energy (DOE) or National Laboratory enterprise environments.
• Experience leading ACAS operations, coordinating scanner maintenance, establishing enterprise scanning procedures, and providing technical direction to other cybersecurity personnel.
• Familiarity with DISA eMASS, Host-Based Security System (HBSS), and Enterprise Security Solutions (ESS).