Computer Network Defense (CND) Security Engineer

Computer Network Defense (CND) Security Engineer
Suitland, MD

Leidos is hiring a Computer Network Defense (CND) Security Engineer to join our team in Suitland, MD. In this role, you will help protect critical Department of Defense networks by monitoring and analyzing security events, investigating cyber threats, performing vulnerability management activities, and supporting advanced cybersecurity technologies across Windows, Linux, and VMware environments. This is an opportunity to work on mission critical systems while collaborating with a highly skilled cyber team.

Primary Responsibilities

• Monitor and analyze security events using Trellix ePO, Splunk, Palo Alto, and RSA.
• Investigate endpoint security alerts, including malware, rogue systems, and removable media events.
• Build dashboards, perform ACAS scans, and assist with vulnerability remediation efforts.
• Apply STIGs, perform system patching, and manage SCAP scans.
• Contribute to RMF documentation and maintain system and network diagrams.

Basic Qualifications

• Bachelor's degree with 8+ years of experience, or a Master's degree with 6+ years of experience. Additional relevant experience or certifications may be considered in lieu of a degree.
• Active TS/SCI clearance (in DISS).
• Active IAT Level II certification (CompTIA Security+ CE preferred).
• Linux administration experience, specifically with Red Hat Enterprise Linux (RHEL).
• 3+ years of Computer Network Defense (CND) experience.
• Experience administering enterprise scale vulnerability management systems, including deploying multi scanner architectures with Tenable Security Center (Tenable.sc) and Nessus Manager.
• Experience managing credentialed scans, performing offline plugin updates in air gapped environments, and deploying Nessus Agents at scale across diverse endpoints.
• Hands on experience with Splunk, Trellix ePO, ACAS, and RMF.

Preferred Qualifications

• Experience with VMware ESXi.
• Experience with ACAS and Nessus.

If you're looking for an opportunity to help defend critical national security systems while working with advanced cybersecurity technologies, we'd love to hear from you.

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NITESONI

If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.

Original Posting:

July 31, 2026

Pay Range:

Pay Range $107,900.00 - $195,050.00

The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.