General informationRequisition # R71616
Locations USA-VA-Chantilly
Posting Date 10/23/2026
Security Clearance Required Top Secret
Remote Type Onsite
Time Type Full time
Description & RequirementsMANTECH seeks a motivated, career and customer-oriented
Information Systems Security Engineer to join our team in
Chantilly, VA. This position will be
onsite. This role can optionally be in
San Diego, CA.The Information Systems Security Engineer (ISSE) will support Risk Management Framework (RMF), security engineering, and cybersecurity lifecycle activities. This role focuses on security control design and implementation, system hardening, technical remediation, continuous monitoring, and security stack operations, with an emphasis on Linux systems and real-time operating systems (RTOS), alongside supporting knowledge of Windows environments.
Responsibilities include but are not limited to:- Assist with or lead the design and integration of technical security controls into system hardware, software, and networking architectures throughout the SDLC
- Work within a technical security engineering team responsible for implementing and maintaining compliant security architectures across complex platforms
- Support RMF execution and system categorization by defining authorization boundaries with network diagrams, hardware/software inventories, data flow documentation, and cryptographic mapping
- Perform hands-on configuration, hardening, log analysis, and remediation on Linux and RTOS environments while enforcing DISA STIGs via automated scripting
- Operate, configure, and maintain Nessus vulnerability scanners and collaborating with ISSOs to analyze scan outputs and determine remediation pathways
- Deploy, configure, and troubleshoot Trellix endpoint security tools across host endpoints to enforce strict media/device control policies and host-based defenses
- Support and maintain enterprise log ingestion and SIEM platforms such as Splunk or Elastic (ELK) to support centralized auditing and continuous monitoring
- Maintain accurate RMF artifacts in eMASS, including the System Security Plan (SSP), POA&M, and supporting technical evidence to support Authorizing Official (AO) decisions
Minimum Qualifications:- Bachelor's degree in IT, Computer Science, Cybersecurity, Computer Engineering, or related field with 2+ years of relevant cybersecurity, system administration or RMF experience; OR High School Diploma/GED with 6+ years of cybersecurity engineering, system administration, or RMF experience
- 2+ years of hands-on experience configuring, hardening, or troubleshooting Linux operating systems, with exposure to RTOS (e.g., QNX, VxWorks) or Windows environments
- Active DoD 8570/8140 IAT Level II certification, e.g., CompTIA Security+ CE, CySA+, SecurityX, CISSP
- Hands-on experience or working knowledge of Nessus vulnerability scanners and Trellix endpoint security tools
- Experience or training with eMASS
- Familiarity with scripting languages (Bash, Python, or PowerShell) for basic task automation, configuration management, or compliance checking
Preferred Qualifications:- Hands-on experience installing, configuring, or operating Splunk, Elasticsearch/Kibana (ELK), or another enterprise log analytics platform
- Understanding of PL2 vs. PL3 security baselines, trust boundaries, and segmentation concepts
- Active industry certifications such as CompTIA Linux+, CGRC, or IAT Level III SecurityX (CASP+), or CISSP
- Experience integrating security into the SDLC or utilizing configuration management tools (Ansible, Puppet, Chef) for STIG automation
Clearance Requirements:- Must have a current or active Top Secret security clearance
Physical Requirements:- Must be able to remain in a stationary position 50% of the time
- Needs to occasionally move about inside the office to access file cabinets, office machinery, etc.
- Frequently communicates with co-workers, management, and customers, and must be able to exchange accurate information in these situations
The projected compensation range for this position is $91,600.00-$153,800.00. There are differentiating factors that can impact a final salary/hourly rate, including, but not limited to, Contract Wage Determination, relevant work experience, skills and competencies that align to the specified role, geographic location (For Remote Opportunities), education and certifications as well as Federal Government Contract Labor categories. In addition, MANTECH invests in its employees beyond just compensation. MANTECH's benefits offerings include, dependent upon position, Health Insurance, Life Insurance, Paid Time Off, Holiday Pay, short-term and long-term Disability, Retirement and Savings, Learning and Development opportunities, wellness programs as well as other optional benefit elections.
