Information System Security Officer - ISSO

Leidos is seeking a TS/SCI with Polygraph cleared Information Systems Security Officer (ISSO) to support our information assurance and cybersecurity mission. The ISSO will be responsible for ensuring the implementation, maintenance, and compliance of security controls for our critical information systems.

• Provide consulting to Agencies on Requests for Service for the design, development, and deployment of Ongoing Assessment, Ongoing Authorization, and other Information Assurance (IA) initiatives.  
• Ensure system security measures comply with applicable government policies
• Ensure that system security requirements are addressed throughout the project and system lifecycle. 
• Review system security A&A package submissions for consistency, completeness and traceability ensuring compliance
• Develop, maintain, and facilitate the appropriate closure of POA&Ms and facilitate with the Agency-designated security Point of Contact (PoC)/ISSO any related remediation activities
• Ensure the development, documentation, and presentation of IS security education, awareness, and training activities for users and others, as appropriate
• Ability to manage multiple high visibility security projects and adjust to quick shifts in customer priorities while meeting all mission requirements
• Familiarity with controlling, labeling, virus scanning, and appropriately transferring data (uploading/downloading)between information systems at varying classification levels;
• Performing Nessus scans and other vulnerability tools and interpreting the results
• Provide support for daily inquiries, data calls and information collection. As well as maintaining status documents and project tracking. 

Key Responsibilities

• Consulting agencies on Requests for Service for the design, development, and deployment of Ongoing Assessment, Ongoing Authorization, and other Information Assurance (IA) initiatives.
• Performing continuous monitoring to enforce client security policy and procedures and creating processes that will provide increased visibility to system owners on impacts to the security posture of systems.
• Monitoring configuration management changes and assessing the impact of modifications and vulnerabilities for each system.
• Ensuring that system security requirements are addressed throughout the project and system lifecycle.
• Ensuring effective controls and processes are in place and working effectively to maintain a strong system security posture.
• Performing vulnerability and risk assessment analyses to support Assessment & Authorization (A&A) activities.
• Reviewing system security A&A package submissions for compliance, consistency, completeness, and traceability.
• Developing, maintaining, and closing POA&Ms while driving remediation efforts alongside the designated security point of contact.
• Auditing and monitoring incident response communications, and other key operational processes for adherence to mandated security policies.
• Ensuring the development, documentation, and presentation of information system security education, awareness, and training activities for users and others.
• Managing multiple high-visibility security projects and adjusting to quick shifts in customer priorities while meeting all mission requirements.
• Controlling, labeling, virus scanning, and appropriately transferring data (uploading/downloading) between information systems at varying classification levels.
• Performing vulnerability assessment scans and interpreting the results.

Qualifications

• Security+ strongly desired
• GSEC Security Essentials
• GIAC Information Security Fundamentals

Requirements:

• Must currently possess an active TS/SCI with Polygraph in order to be considered. Candidates without this level clearance will not be considered.
• BA or BS degree 8+ years of experience, or Master's Degree and 5 years of experience, in a broad range of assignments with 4 years focused on security and/or ISSO work.
• CISSP
• Will substitute additional experience and certifications in lieu of degree.

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:

November 12, 2026

Pay Range:

Pay Range $107,900.00 - $195,050.00

The 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.