ISSO

Leidos Holding$107K — $195K *
Aerospace & Defense
5 - 7 years of experience
Job Overview by Ladders

Qualifications

  • 8 years of relevant experience with a Bachelor's degree or 6 years with a Master's; additional years may replace degree requirements
  • Experience applying ICD-503 Risk Management Framework
  • Proficient in using XACTA for accreditation package management
  • Understanding of DoD and Intelligence Community security policies
  • Ability to review and analyze ATO documentation
  • Excellent time management skills and effective communication abilities
  • Experience with IT Service Management products like ServiceNow or Remedy

Responsibilities

  • Author and update accreditation packages to maintain ATO compliance
  • Validate customer documentation for ATO packages and ensure usability
  • Maintain security documentation in XACTA and CMDB tools
  • Develop and track Plans of Action & Milestones (POA&Ms) for risk management
  • Collaborate with system administrators for vulnerability remediation
  • Communicate effectively with stakeholders across different levels
  • Mentor team members on security best practices

Benefits

  • Dynamic work environment that encourages innovation and proactive solutions
  • Opportunities for professional development and continuing education
  • Support for work-life balance with flexible hours
  • Engagement in meaningful projects for the DOD with a clear impact
  • Access to cutting-edge technology and resources
Full Job Description

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 customers 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 customers 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 customers 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) 6 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 youre looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo 6 because the mission demands it. Were not hiring followers. Were recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. Were already at step 30 6 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 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 $107,900.00 - $195,050.00

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 Holding

Leidos Holding Careers

Joining Leidos Holding presents an unparalleled opportunity to advance one's career with a leader in innovation and technology. The company offers a plethora of job opportunities aimed at fostering professional growth and development in a diverse and inclusive environment.

Explore Career Opportunities

Leidos Holding is actively seeking skilled professionals who are passionate about leveraging their expertise to drive innovation and leadership in their fields. With a variety of open positions, Leidos Holding provides a platform for individuals to challenge themselves in a dynamic work environment.

Innovation and Professional Growth

At Leidos Holding, innovation is at the core of everything they do. Employees are encouraged to think creatively and push boundaries. The company supports this drive for innovation through comprehensive professional development and diversity training programs that are designed to enhance skills and foster leadership.

Commitment to Diversity and Inclusion

Leidos Holding is committed to creating a workplace where diversity is not only recognized but celebrated. With a culture that values and promotes diversity, Leidos Holding ensures that all team members have the opportunity to contribute, learn, and grow.

Internship Programs

For those starting their career, Leidos Holding offers internship programs that provide a robust foundation in the industry. Internships are a great way to develop essential skills, gain valuable work experience, and build professional networks.

Benefits and Culture

Employees at Leidos Holding enjoy a range of benefits designed to support their professional and personal lives. The company culture is built on a foundation of respect and integrity, providing a supportive and collaborative environment where every team member is valued.

Join the Team

Leidos Holding is hiring! Explore job opportunities that match your skills and interests. Leidos Holding looks for driven, curious, and innovative individuals to join their team. Positions are available across various disciplines and experience levels.

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Prepare for Your Interview

To prepare for an interview at Leidos Holding, candidates should familiarize themselves with the company's missions and values, update their resumes, and be ready to discuss how their background and skills align with the position they are applying for.

Networking and Career Advancement

Leidos Holding encourages its employees to engage in networking within the company to discover new opportunities for career advancement. The leadership team at Leidos Holding is dedicated to supporting employees in their career paths with ample opportunities for networking and growth.

Explore Leidos Holding Jobs and Careers

Discover the exciting career opportunities at Leidos Holding today. With a commitment to employee growth, innovation, and diversity, Leidos Holding is the perfect place to advance your career. Check out the latest job listings and find your perfect fit at Leidos Holding.

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