Information Systems Security Engineer; ISSE) Linux​/RHEL

Position: Information Systems Security Engineer (ISSE) Linux/RHEL
Job Title:

Information Systems Security Engineer (ISSE) Linux/RHELJob Category:
Security Time Type:
Full time Minimum Clearance Required to Start: TS/SCI Employee Type:
Regular Percentage of

Travel Required:

Up to 25%
Type of Travel:
Continental US*
*
* The Opportunity:

We are seeking a highly motivated, Linux-focused Information Systems Security Engineer (ISSE) to support the security, accreditation, and continuous monitoring of mission-critical systems operating within classified environments.

The ideal candidate combines cybersecurity engineering expertise with hands-on Red Hat Enterprise Linux (RHEL) administration skills. This position requires an individual comfortable working directly with Linux systems to implement security controls, troubleshoot configurations, remediate vulnerabilities, and support Risk Management Framework (RMF) compliance.

Working alongside systems engineers, software developers, and cybersecurity professionals, you will help design, implement, and maintain secure solutions supporting critical national security missions.

This position requires onsite support 100% of the time in Sterling, VA. Domestic and international travel opportunities may be available.

Responsibilities:

Perform hands-on security engineering, configuration, troubleshooting, and hardening of Red Hat Enterprise Linux (RHEL) systems

Implement, validate, and maintain DISA STIG compliance, including executing SCAP scans, analyzing findings, and remediating security vulnerabilities

Troubleshoot Linux security configurations involving SELinux, SSH, permissions, authentication, system services, and networking

Lead and support Assessment and Authorization (A&A) activities to achieve and maintain Authorization to Operate (ATO) under the Risk Management Framework (RMF)
Develop and maintain security documentation, including System Security Plans (SSPs), Security Assessment Reports (SARs), Security Control Traceability Matrices (SCTMs), and Plans of Action and Milestones (POA&Ms)
Conduct security assessments and continuous monitoring activities aligned with ICD 503, NIST 800-53, CNSSI, and applicable DoD requirements

Collaborate with systems, network, software, and Dev Ops engineers to integrate security requirements throughout the System Development Life Cycle (SDLC)
Evaluate system architectures, infrastructure changes, and software configurations to identify security risks and recommend mitigations

Develop Bash or Python scripts to automate security compliance, vulnerability assessments, and routine administrative tasks.

Qualifications:

Required:

Required5+ years of combined experience in cybersecurity engineering, information assurance, Linux systems administration, or related technical disciplines

Minimum 2 years of hands-on Linux administration experience, preferably with RHEL 8/9

Practical Linux command-line proficiency, including file system management, permissions, user administration, package management (DNF/YUM), systemd services, log analysis, SSH, and basic network troubleshooting

Experience implementing Linux DISA STIGs, executing SCAP scans, and performing vulnerability remediation

Working knowledge of Linux security technologies, including SELinux, firewalld, authentication, and access controls

Experience with Bash scripting and/or Python for system administration or security automation

Strong understanding of RMF, ICD 503, NIST 800-53, and the ATO lifecycle

DoD 8570/8140 IAT Level II certification (Security+ CE, CySA+, SSCP, or equivalent applicable certification)
Bachelor's degree in a technical discipline or equivalent relevant experience

Active Top Secret clearance with SCI eligibility.

Desired:

Red Hat Certified System Administrator (RHCSA) or Red Hat Certified Engineer (RHCE) certification.

Experience supporting RHEL systems in classified, disconnected, or air-gapped environments.

Familiarity with Puppet, Ansible, Red Hat Satellite, or Red Hat Identity Management (IdM/FreeIPA).

Experience with ACAS, Nessus, SCAP Compliance Checker, or similar vulnerability assessment tools

Experience with Git, Git Lab, Dev Sec Ops , and automated compliance solutions

Experience supporting Cross Domain Solutions (CDS) or other highly secure mission systems

Advanced cybersecurity certifications such as CISSP or CASP+-What You Can Expect: A culture of integrity.

At CACI, we place character and innovation at the center of everything we do. As a valued team member, you’ll be part of a high-performing group dedicated to our customer’s missions and driven by a higher…