Cloud Security Administrator - RHEL

Help secure mission-critical cloud environments supporting our nation's cyber defense.

Leidos is seeking a Cloud Security Administrator with senior-level RHEL administration experience to support the U.S. Army C5ISR Cyber Security Service Provider (CSSP). In this role, you'll help secure and sustain AWS cloud environments by managing security controls, identifying vulnerabilities, coordinating remediation, and supporting continuous compliance monitoring.

You'll collaborate with cloud engineers, cybersecurity specialists, and mission partners to strengthen cloud security, streamline remediation, and maintain operational readiness across enterprise environments.

If you're passionate about AWS security, vulnerability management, and protecting critical defense infrastructure in RHEL environment, this is an opportunity to apply your expertise to a mission that matters.

Location: Adelphi, MD | Hybrid (3 Days Onsite)

Clearance: U.S. citizenship with an active Secret Required | TS/SCI Required for Position

Primary Responsibilities

• Administer, monitor, and maintain cloud security controls across AWS 2.0 and CSSP subscriber environments.
• Ability to diagnose and resolve Linux operating-system, service, storage, networking, authentication, and application issues.
• Identify, assess, track, and coordinate remediation of cloud vulnerabilities, misconfigurations, and compliance findings.
• Manage AWS security capabilities, including IAM, CloudTrail, CloudWatch, Security Hub, GuardDuty, KMS, and VPC security controls.
• Support Risk Management Framework (RMF), Authorization to Operate (ATO), and continuous monitoring through security assessments, control validation, and compliance documentation.
• Conduct security configuration reviews across AWS resources, Linux and Windows systems, and supporting cloud infrastructure.
• Support onboarding of CSSP subscribers into centralized logging, vulnerability management, Elastic Agent Defend, and other security services.
• Coordinate security patching, access reviews, change management, incident response, and ongoing security operations.
• Develop and maintain security procedures, operational runbooks, compliance evidence, and technical documentation.

Basic Qualifications

• Bachelor's degree with 8+ years of relevant experience or master's degree with 4+ years of relevant experience. Additional relevant experience may be considered in lieu of a degree.
• Hands-on experience administering security controls in AWS or other enterprise cloud environments.
• Working knowledge of AWS security services, including IAM, CloudTrail, CloudWatch, Security Hub, GuardDuty, Systems Manager, KMS, and VPC security controls.
• Experience with vulnerability management, security assessments, compliance monitoring, patch management, and remediation tracking.
• Demonstrated hands-on experience administering Red Hat Enterprise Linux (RHEL) systems in production or enterprise environments.
• Familiarity with Linux and Windows security administration, including host-level and cloud security findings.
• Experience using Ansible to automate routine system-administration tasks, such as configuration changes, account management, and compliance remediation.
• Understanding of DoD cybersecurity requirements, RMF/ATO, NIST SP 800-53, and DISA STIG/SRG standards.
• Experience with SIEM, endpoint security, enterprise logging, security monitoring, and ticketing platforms.
• Strong analytical, troubleshooting, documentation, and communication skills.
• Ability to meet applicable DoD 8140 qualification requirements at start and obtain required CSSP and Computing Environment certifications within 90 days, as applicable to the assigned work role.
• U.S. Citizenship with an active Secret security clearance required at start, with TS/SCI required for the position, subject to program access and eligibility requirements.

Preferred Qualifications

• Experience securing DoD cloud environments, including AWS GovCloud, IL4/IL5/IL6, Cloud One, or ECMA.
• Hands-on experience with Tenable.sc/ACAS, Elastic Security, Elastic Agent Defend, AWS Security Hub, or GuardDuty.
• Experience supporting RMF authorization packages, ATO assessments, and continuous-monitoring compliance activities.
• DoD 8140-aligned certification, such as CISSP, or equivalent certification appropriate to the assigned work role.
• AWS cloud or security certification and familiarity with scripting, automation, or infrastructure as code.

If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.

Original Posting:

November 6, 2026

Pay Range:

Pay Range $107,900.00 - $195,050.00

The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.