> Markdown version of [/jobs/ext/4026643-information-systems-security-engineer-isse-linux-rhel](https://www.wearedevelopers.com/jobs/ext/4026643-information-systems-security-engineer-isse-linux-rhel). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Information Systems Security Engineer (ISSE) Linux/RHEL - **Company:** Caci Inc - **Location:** Sterling, VA, United States - **Experience:** Experienced - **Salary:** $86,600.0 - $181,800.0 - **Contract:** Permanent contract - **Skills:** Secure Shell (SSH), Systems Engineering, User Authentication, Bash Shell, Cyber Security, System Configuration, Linux, DevOps, Identity and Access Management, Python (Programming Language), Linux System Administration, Linux Commands, Linux Security Modules, Log Analysis, Package Management Systems, Systems Development Life Cycle, Red Hat Enterprise Linux, Ansible, Security Content Automation Protocol, Systems Architecture, Software Vulnerability Management, Scripting, SARS Software Products, Gitlab, Git, Selinux, Nessus, Puppet, Scap Compliance Checker, Devsecops, Security Orchestration, Automation & Response, User Administration, Vulnerability Analysis - **Published:** October 30, 2026 - **Apply:** https://www.clearancejobs.com/jobs/9279443/information-systems-security-engineer-isse-linuxrhel ## About the Role 5+ 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 filesystem 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, GitLab, DevSecOps, and automated compliance solutions Experience supporting Cross Domain Solutions (CDS) or other highly secure mission systems Advanced cybersecurity certifications such as CISSP or CASP+ ## Description 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., 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 DevOps 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.