Information System Security Officer; ISSO

Join a Mission-Driven Team at Leidos:

At Leidos, we deliver cutting-edge solutions through the dedication of our diverse and talented workforce. United by a shared commitment to our customers’ success, we empower our teams, support our communities, and operate sustainably. Guided by our Mission, Vision, and Values, we strive to always do the right thing-for our customers, our people, and our world.

We’re seeking a dynamic and experienced Information System Security Officer (ISSO) to support a high-impact program providing Information Assurance services to the U.S. Space Force
. This role offers a unique opportunity to contribute to a critical national defense mission while working in a fast-paced, innovative IT environment.

This position reports directly to the Program Manager.

• Collaborate daily with the ISSM to provide expert cybersecurity guidance and recommendations
• Oversee classified processing tasks, ensuring compliance with established standards
• Conduct system audits and execute Continuous Monitoring (Con Mon) activities
• Lead and support the Risk Management Framework (RMF) authorization process, including development and maintenance of the Body of Evidence (BoE)
• Manage Configuration Management (CM) activities for hardware, software, firmware, and security‑relevant functions
• Analyze vulnerability scans, implement DISA STIGs, and ensure secure system configurations
• Interpret and apply DoD cybersecurity policies and procedures
• Review and recommend remediation actions for Plan of Action and Milestones (POA&M) to mitigate risks and achieve Authorization to Operate (ATO)

• Bachelor’s degree and 8+ years of relevant experience (additional experience, training, and/or certifications may substitute degree requirement)
• U.S. Citizenship;
  Currently possess an Active DoD Top Secret clearance with SCI eligibility
• Proficiency with DCSA eMASS, SCAP, ACAS, and Nessus Network Monitor (NNM)
• Strong understanding of RMF, SDLC, and A&A documentation development
• Experience with DCSA and Special Access Program (SAP) A&A processes
• Ability to apply government security regulations (FIPS, NIST, NISPOM, JSIG, ICDs) to information systems
• Expertise in securing Windows, Linux, and UNIX environments using Active Directory and Group Policy
• Exceptional analytical, problem‑solving, and communication skills
• Strong attention to detail and organizational discipline
• Proven ability to manage multiple priorities independently
• Must obtain DoD 8140 (DoD 8570.01) IAT II certification within 6 months of hire

• Experience with the implementation or both DoDD 8570 and DoDI 8140 certification processes
• Experience supporting DoD customers and mission requirements
• Hands‑on experience with Trellix modules and SIEM solutions
• Knowledge of DCSA XACTA and CORE platforms
• RMF package development for NIPR, SIPR, and JWICS networks
• Understanding of DoD military standards and operational environments
• Ability to adapt to evolving mission needs and technical landscapes

This role is ideal for cybersecurity professionals who thrive in mission‑critical environments and are passionate about protecting national assets. If you’re ready to make a meaningful impact, we’d love to hear from you.

At Leidos, we don’t want someone who "fits the mold"-we want someone who melts it down and builds something better. This is a role for the restless, the over‑caffeinated, the ones who ask, “what’s next?” before the dust settles on “what’s now.”

If you’re already scheming step 20 while everyone else is still debating step 2... good. You’ll fit right in.

January 6, 2026

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Leidos is an industry and technology leader serving government and commercial customers with smarter, more efficient digital and mission innovations. Headquartered in Reston, Virginia, with 47,000 global employees, Leidos reported annual revenues of approximately $16.7 billion for the fiscal year ended , 2025. For more information, visit

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