Junior Information Systems Security Officer

Leidos has a new and exciting opportunity for a Junior Information Systems Security Officer (ISSO) in our Intelligence Sectors, Cyber & Analytics Business Area (CABA). Our talented team is at the forefront in Security Engineering, Computer Network Operations (CNO), Mission Software, Analytical Methods and Modeling, Signals Intelligence (SIGINT), and Cryptographic Key Management.

At Leidos
, we offer competitive benefits, including Paid Time Off, 11 paid Holidays, 401K with a 6% company match and immediate vesting, Flexible Schedules, Discounted Stock Purchase Plans, Technical Upskilling, Education and Training Support, Parental Paid Leave, and much more.

We are seeking a driven Cybersecurity Professional to support Information Assurance (IA) initiatives and maintain system security integrity. You will actively assist with security operations, conduct risk assessments, and contribute to continuous compliance using the DoD Risk Management Framework (RMF) to safeguard classified information systems.

• Oversee daily security configurations for classified processing environments.
• Conduct rigorous vulnerability scans and comprehensive risk assessments.
• Evaluate new security solutions to strengthen the overall system architecture.

• Guide systems through the full RMF Authorization to Operate (ATO) lifecycle.
• Author System Security Plans (SSPs) and Risk Assessment Reports.
• Maintain precise Security Control Traceability Matrices (SCTMs) and A&A packages.

• Administer strict Configuration Management (CM) for software, hardware, and firmware.
• Audit security controls to confirm baseline integrity across enclaves.
• Analyze the security impact of proposed technical system changes.
• Collaboration & Improvement
• Provide technical guidance on complex security policies to stakeholder groups.
• Proactively hunt for weaknesses and deploy strategic solutions to raise resilience.
• Partner with engineering teams to embed security best practices early.

Bachelor’s Degree (Computer Science, Cybersecurity, IA, or related) + 2+ years of relevant experience. OR Master’s Degree (Computer Science, Cybersecurity, IA, or related) + 0+ years of experience. or High School Diploma / Equivalent + 6+ years of direct experience (considered case-by-case).

DoD 8140 Compliant at IAM Level I/II or IAT Level III (e.g., CISSP, CASP or SecurityX, Security+) by time clearance is awarded

• Excellent interpersonal communication skills.
• Strong organizational and goal-oriented focus.
• Critical-thinking, collaborative, team-first mindset.

Ability to obtain a TS/SCI with Polygraph required

• Familiarization with Information Assurance software tools (e.g., Nessus, Splunk, Service Now, XACTA, eMASS).
• Direct or indirect exposure to the specific customer domain and operating environment.
• Prior technical background in System Administration, Network Engineering, or Systems Engineering.

September 22, 2026

For U.S. Positions:
While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.

Pay Range $69,550.00 - $

The Leidos pay range for this job level is a general guideline onlyand 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…