Information System Security Officer (ISSO)

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 systemsMust 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.DABAOPP1If 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:August 11, 2026For 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 - $157,450.00The 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.SummaryLocation: Lorton, VA; Oklahoma City, OKType: Full time