Linux/RHEL ISSE Security Engineer — RMF/A&A Expert

CACI International Inc; Sterling (VA); On-site; USD 87,000 - 182,000; Full time

Job summary

CACI International Inc in Sterling, VA is seeking a Linux-focused Information Systems Security Engineer (ISSE) to support security, accreditation, and continuous monitoring of mission-critical systems in classified environments. You will apply RMF, implement DISA STIGs, and harden Red Hat Enterprise Linux.

The role requires hands-on Linux administration, scripting in Bash or Python, and collaboration with engineers across SDLC to ensure secure configurations and ATO readiness.

Qualifications

• 5+ years of cybersecurity engineering, information assurance, or Linux administration.
• 2+ years hands-on Linux administration, preferably RHEL 8/9.
• Experience implementing Linux DISA STIGs and vulnerability remediation.
• Knowledge of RMF, ICD 503, NIST 800-53, and ATO lifecycle.
• DoD 8570 IAT Level II certification or equivalent required.
• Active TS/SCI with eligibility.

Responsibilities

• Perform hands-on security engineering, configuration, and hardening of RHEL systems.
• Implement and maintain DISA STIG compliance; run SCAP scans and fix findings.
• Troubleshoot SELinux, SSH, permissions, services, and network configs.
• Lead A&A activities to achieve and maintain ATO under RMF.
• Develop security docs: SSPs, SARs, SCTMs, and POA&Ms.
• Collaborate across SDLC with engineers to embed security requirements.
• Develop Bash or Python scripts to automate security tasks.

Skills

Linux System Admin

DISA STIGs

SCAP Scans

RMF ATO

SELinux

Bash/Python

DoD 8570 IAT II

Security clearance

RHEL 8/9

Vulnerability remediation

Education

Bachelor's degree in a technical discipline

DoD 8570 IAT II certification

RHCSA/RHCE certification

Tools

Puppet

Ansible

Red Hat Satellite

IdM/FreeIPA

ACAS

Nessus

SCAP Compliance Checker

Git/GitLab

Job description

CACI International Inc in Sterling, VA is seeking a Linux-focused Information Systems Security Engineer (ISSE) to support security, accreditation, and continuous monitoring of mission-critical systems in classified environments. You will apply RMF, implement DISA STIGs, and harden Red Hat Enterprise Linux.

The role requires hands-on Linux administration, scripting in Bash or Python, and collaboration with engineers across SDLC to ensure secure configurations and ATO readiness.