Information System Security Officer (ISSO)

Leidos; Lorton (VA); On-site; USD 87,000 - 157,000; Full time

Job summary

Leidos Defense Sector seeks an Information System Security Officer (ISSO) to support a fast-paced Air Force LCMC program. This on-site role oversees the cybersecurity posture of DoD information systems, develops policies, and conducts risk assessments to ensure compliance with DoD standards.

You will collaborate with cross-functional teams, maintain RMF accreditation, and provide security training. Required Top Secret/SCI eligibility and DoD certifications.

Qualifications

• The candidate has a U.S. citizenship and active Top Secret clearance with SCI eligibility.
• Degree: Bachelor’s (4+ years) or Master’s (2+ years) with relevant cybersecurity experience.
• In-depth knowledge of DoD cybersecurity policies and frameworks (NIST 800-53, RMF, FISMA, JSIG, ICD 503/705).
• Experience with cloud computing and obtaining an ATO for cloud-based systems.
• Must hold a DoD 8140 Intermediate certification (e.g., Cloud+, Security+).
• Experience in system security engineering, risk management, and vulnerability assessments.
• Proficiency in network security, security controls, and SIEM/IDS/IPS tools.
• Ability to work independently and communicate security findings effectively.

Responsibilities

• Collaborate daily with the ISSO and provide cybersecurity guidance.
• Develop, implement, and maintain security policies, procedures, and documentation per DoD standards.
• Oversee the security posture of DoD information systems for confidentiality, integrity, and availability.
• Conduct risk assessments, vulnerability assessments, and security audits with remediation strategies.
• Manage continuous monitoring of security controls and protect data (classified and unclassified).
• Coordinate with cross-functional teams to enforce security controls and best practices.
• Ensure RMF accreditation is maintained and compliant with applicable requirements.
• Serve as primary security contact for incident response and reporting to leadership and government customers.
• Provide security training and awareness programs for operational personnel.
• Maintain SSPs, risk assessments, and POA&Ms with up-to-date documentation.
• Stay current with emerging cybersecurity threats and trends to adapt the program.

Skills

Top Secret Clearance

Cloud Security

DoD RMF/NIST

Vulnerability Assessments

Security Engineering

Network Security

DoD 8140 cert

Security Policies

Independent Worker

Communication Skills

Education

Bachelor's degree

Master's degree

Tools

SIEM

Firewalls

IDS/IPS

Endpoint Security

Job description

Description

The Defense Sector at Leidos is looking for an Information System Security Officer (ISSO) to support a fast-paced program with the Air Force Life Cycle Management Center. This role involves supporting the delivery of comprehensive IT and support services to ensure mission success while adhering to DoD standards and regulations. The ISSO will oversee the cybersecurity posture of DoD information systems, ensuring compliance with DoD security standards and protecting sensitive data. The ISSO will develop and implement security policies, conduct risk assessments, manage system accreditations (RMF), and execute continuous monitoring efforts. This role requires collaboration with cross-functional teams to enforce security controls and manage continuous monitoring. The ISSO will also maintain security documentation and ensure ongoing compliance with applicable regulations. The ISSO will be expected to be proficient technically & to perform hands‑on cybersecurity tasks.

This position will require 100% on‑site work with no remote work supported.

Primary Responsibilities:

• Collaborate daily with the ISSM to provide expert cybersecurity guidance and recommendations.
• Support the development, implementation, and maintenance of security policies, procedures, and documentation to ensure compliance with DoD security standards and regulations (e.g., NIST, RMF, FISMA, JSIG).
• Oversee the security posture of DoD information systems, ensuring they meet cybersecurity requirements for confidentiality, integrity, and availability.
• Perform risk assessments, vulnerability assessments, and security audits to identify system vulnerabilities and provide remediation strategies.
• Manage and conduct continuous monitoring of security controls, ensuring the protection of classified and unclassified data.
• Coordinate with cross‑functional teams (engineering, IT, operations) to implement and enforce security protocols and best practices.
• Ensure the accreditation process for DoD systems (e.g., RMF accreditation) is completed and continually maintained in compliance with all applicable requirements.
• Act as the primary point of contact for security‑related issues, assisting in incident response and reporting to senior management and government customers.
• Provide security training and awareness programs for personnel involved in the operation of DoD systems.
• Maintain and track security documentation, including system security plans (SSPs), risk assessments, and Plan of Actions & Milestones (POA&Ms).
• Stay current with emerging cybersecurity threats, vulnerabilities, and trends to ensure the program adapts to evolving security challenges.

Basic Qualifications:

• US Citizen with at least an active Top Secret Clearance with the ability to obtain an SCI prior to your start date.
• Bachelor’s degree with 4+ years of experience or a Master’s degree with 2+ years of experience. Additional experience may be considered in lieu of a degree.
• In‑depth knowledge of DoD cybersecurity policies, frameworks, and compliance standards (e.g., NIST 800‑53, RMF, FISMA, ICD 503/705, JSIG, DAAPM).
• In‑depth experience with cloud computing and building/maintaining an ATO for cloud‑based information systems
• Must have a DoD 8140 Intermediate certification (e.g. Cloud+, Security+, etc.).
• Experience with system security engineering, risk management, and vulnerability assessments.
• Strong understanding of network security, security controls, and common cybersecurity tools (e.g., firewalls, IDS/IPS, SIEM, endpoint protection).
• Ability to work independently and collaborate effectively with cross‑functional teams.
• Strong communication skills, including the ability to create and present detailed security reports to stakeholders.
• Interest in continuous learning and professional development in cybersecurity.

Preferred Qualifications:

• US Citizen with an active TS/SCI security clearance.
• DoD 8140 Advanced certification e.g. CISSP (Certified Information Systems Security Professional), CISM (Certified Information Security Manager), etc.
• Experience with JSIG implementation of the Risk Management Framework (RMF) for DoD system accreditations and continuous monitoring processes.
• Experience in managing security for complex DoD programs or mission‑critical systems.
• Familiarity with cloud security practices and systems, particularly in a hybrid or government cloud environment.
• Experience with security tools for vulnerability scanning, penetration testing, and security auditing.
• Cloud security certifications (e.g. Azure Security Technologies or AWS Certified Security Specialty).
• Experience with configuration management and change management processes in a secure environment.

Original Posting:

August 11, 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:

Pay Range $87,100.00 - $157,450.00

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 with market data, applicable bargaining agreement (if any), or other law.

About Leidos

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 January 3, 2025. For more information, visit www.Leidos.com.

Pay and Benefits

Pay and benefits are fundamental to any career decision. That's why we craft compensation packages that reflect the importance of the work we do for our customers. Employment benefits include competitive compensation, Health and Wellness programs, Income Protection, Paid Leave and Retirement. More details are available at www.leidos.com/careers/pay-benefits.

Securing Your Data

Beware of fake employment opportunities using Leidos’ name. Leidos will never ask you to provide payment‑related information during any part of the employment application process (i.e., ask you for money), nor will Leidos ever advance money as part of the hiring process (i.e., send you a check or money order before doing any work). Further, Leidos will only communicate with you through emails that are generated by the Leidos.com automated system – never from free commercial services (e.g., Gmail, Yahoo, Hotmail) or via WhatsApp, Telegram, etc. If you received an email purporting to be from Leidos that asks for payment‑related information or any other personal information (e.g., about you or your previous employer), and you are concerned about its legitimacy, please make us aware immediately by emailing us at [e-mail].

If you believe you are the victim of a scam, contact your local law enforcement and report the incident to U.S. Federal Trade Commission.

Commitment to Non-Discrimination

All qualified applicants will receive consideration for employment without regard to sex, race, ethnicity, age, national origin, citizenship, religion, physical or mental disability, medical condition, genetic information, pregnancy, family structure, marital status, ancestry, domestic partner status, sexual orientation, gender identity or expression, veteran or military status, or any other basis prohibited by law. Leidos will also consider for employment qualified applicants with criminal histories consistent with relevant laws.