ISSO

Unleash Your Potential At Leidos, we deliver innovative solutions through the efforts of our diverse and talented people who are dedicated to our customer’s success. We empower our teams, contribute to our communities, and operate sustainably. Everything we do is built on a commitment to do the right thing for our customers, our people, and our community. Our Mission, Vision, and Values guide the way we do business.  If this sounds like an environment where you can thrive, keep reading!  The Mission Leidos is seeking an Information System Security Office (ISSO) to support a large enterprise IT contract for the DOD. The ISSO will be responsible for reviewing and maintaining existing Authority to Operate (ATO) documentation throughout the sustainment portion of the system lifecycle. They will utilize the XACTA system to update documentation in the Risk Management Framework (RMF) System Security Package (SSP), verify systems are operating in their intended manner, and validate administrator permissions and access to systems under their purview This role requires an individual that is familiar with security accreditation frameworks and directives (e.g. NIST, RMF, Common Criteria, DoD, and Intelligence Community Directives (ICDs)) and works to mitigate risks by applying security controls effectively to maintain an acceptable degree of operational risk across multiple enclaves in an enterprise environment. The ISSO will promote security best practices, identify and articulate process improvement and procedures updates, and conduct testing and assessments to sustain required accreditations. Additionally, the ISSO  will assist with tracking, documenting, and remediating vulnerabilities identified by the customer’s Cyber Security division and direct remediation efforts for system administrator staff, provide status updates to government and program leadership, and update relevant RMF packages as required. Primary Tasks Author, review, and update accreditation packages and supporting documentation to maintain existing ATO state for all systems operating in the production environment that follow all government, IC, DoD, DISA, NIST, or industry standards and policies Review documentation provided by the customer’s Engineering division as part of the initial ATO package to validate all documents are available and useable in their current state Maintain SSPs and related configuration records in customer’s XACTA system and Service Now or other CMDB tool Develop, monitor, and update Plan of Action & Milestones (POA&Ms) to document open risks and vulnerabilities through remediation or mitigate Can work independently as well as collaboratively to drive security process improvements to streamline the process, increase the security posture of the enterprise, and ensure due diligence at all times Comfortable communicating officially and unofficially via briefings, meetings, emails, or other collaboration technologies, with Leidos program leadership and government leadership  Has in-depth understanding of information security technical principles, theories, concepts and their application across a range of enterprise services and systems Coordinates all A&A renewal activities with the DAO, DAOR, or other representatives from the Cyber Security division to maintain proper accreditation throughout the life of the system   Review, update, and maintain CONOPs, Disaster Recovery, and other required plans for each system to reflect the evolving enterprise Coordinate with System Administrators and other operations and engineering staff to remediate all vulnerabilities and report results to the Cyber Security division.  Document, track, and obtain approvals for open vulnerabilities that cannot be remediated through the use of POA&Ms, Risk Acceptance requests, or other customer-mandated processes and forms  Mentor coworkers, system administrators, program and government leadership on evolving security best practices and potential impacts on production systems Basic Qualifications Candidates should demonstrate the following: Practical experience understanding and applying ICD-503 Risk Management Framework Experience with XACTA to track, document, and validate accreditation packages Understanding of DoD and IC security policies and mandates Experienced with reviewing existing ATO documentation, identifying missing or outdated information, and coordinating with relevant support teams to obtain necessary information Time management skills Strong oral and written communication skills Track record of working effectively individually, with peers, and with outside support elements Experience with IT Service Management (ITSM) products such as ServiceNow or Remedy.   Clearance Requirement Due to the nature of the government contracts we support, US Citizenship is required. TS/SCI with Polygraph required for Position OR TS/SCI and willingness to obtain and maintain a polygraph. Education and Experience: Bachelor's degree in a technical field with at least 8 years of prior relevant experience or Masters with 6 years of prior relevant experience.  Additional years of experience may be considered in lieu of degree. Candidate must, at a minimum, meet DoDM 8140.03 (previously DoD 8570) – IT System Admin Intermediate certification requirements (Cloud+, GICSP, SSCP, Security+ CE, GSEC, or higher) Preferred Qualifications Active Certified Information Systems Security Professional (CISSP) or ISACA Certified Information Security Manager (CISM)  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: June 22, 2026 For U.S. Positions: While subject to change based on business needs, Leidos rea