Senior Information System Security Engineer

General information

Requisition # R66840 Locations USA-DC-Washington Posting Date 03/27/2026 Security Clearance Required TS/SCI Remote Type Onsite Time Type Full time

Description & Requirements

Unlock the secrets of intelligence with MANTECH! Join a dynamic team at the forefront of national security, providing advanced solutions to government intelligence agencies. Since 1968, we’ve been solving the toughest challenges with groundbreaking tech. Explore thrilling projects in Digital Transformation, Cybersecurity, IT, Data Analytics and Software Development. Elevate your career and make a difference. Your adventure begins now—unleash your potential with MANTECH!

MANTECH seeks a motivated, career and customer-oriented Senior Information System Security Engineer (ISSE) to join our team in Washington, D.C., Chantilly, VA or Quantico, VA.

Responsibilities include, but are not limited to:

• Define and implement cybersecurity requirements, architectures, and secure system designs across information systems and network environments
• Design, develop, and integrate security solutions, including Cross Domain Solutions (CDS), to support secure data flow and system interoperability
• Implement network security controls and countermeasures to ensure confidentiality, integrity, availability, authentication, and non-repudiation
• Identify, assess, and mitigate system and network vulnerabilities, recommending enhancements to strengthen overall security posture
• Maintain and track vulnerability data, POA&Ms, and remediation activities using GRC and enterprise tracking tools
• Lead stakeholder engagement through office hours, guidance, and updated procedures to support vulnerability management and compliance efforts
• Provide rapid response to data calls, RFIs, and leadership inquiries, including escalation and reporting of high-risk or non-compliant remediation actions

Minimum Qualifications:

• Must meet one of the following levels of experience: A high school diploma/GED and 14 years’ experience, an Associate’s degree and 10 years’ experience, a Bachelors degree and 8 years’ experience, or a Master’s and 6 years’ experience.
• Hold at least one of the following certifications: Certified Information Systems Security Professional (CISSP) (or Associate), CompTIA Advanced Security Practitioner (CASP) CE, Certified Secure Software Lifecycle Professional (CSSLP), CISSP- Information System Security Engineering Professional (ISSEP), Certified Information Security Manager (CISM), or CISSP- Information System Security Architecture Professional (ISSAP). 
• Familiarity with the use and operation of security tools including: Tenable Nessus and/or Security Center, IBM Guardium, HP WeblInspect, Network Mapper (NMAP), and/or similar applications.
• Working knowledge of the National Institute of Standards and Technology (NIST) Risk Management Framework (RMF) and ATO processes.
• Experience with vulnerability management programs,