Senior ISSO: RMF, ACAS & DoD Systems Expert

Apavo Corporation; Oakton (VA); On-site; USD 120,000 - 180,000; Full time

Job summary

Apavo Corporation seeks an Information Systems Security Officer (ISSO) to ensure secure operation of multi-enclave IT/R&D systems across classifications. You will advise system owners on security posture and lead RMF processes using ACAS and DoD tooling to maintain active Authority to Operate without disrupting critical research.

This on-site role in Oakton, VA requires TS eligibility, hands-on ACAS experience, and collaboration with the ISSM and researchers to remediate findings and support

Qualifications

• Bachelor's degree in Cybersecurity/IT or related field with 5–7+ years as ISSO or senior DoD RMF role.
• Active Top Secret clearance with SCI eligibility; CI/Full-Scope Poly highly preferred.
• DoD 8570.01-M/8140.03 IAM Level II or III certifications (CISSP, CISM, CASP+, etc.).
• ACAS experience: run scans, interpret results, manage asset lists.
• RMF/NIST knowledge: DoD RMF, NIST 800-53/37/171, DISA STIG implementation.
• ATO artifacts management in eMASS or Xacta; familiarity with SCC/STIG Viewer.
• Excellent written and verbal communication; liaise with stakeholders.

Responsibilities

• Develop and maintain RMF packages (SSP, SAR, RAR, POA&M) in eMASS/XACTA.
• Execute ACAS scans and analyze results to identify vulnerabilities.
• Translate findings into remediation steps with system admins and researchers.
• Oversee Continuous Monitoring and review SIEM logs for compliance.
• Support secure data transfers for air-gapped enclaves and multi-enclave environments.
• Coordinate with ISSM and incident response teams on security incidents.
• Assist with third-party assessments and ATO validations.

Skills

ACAS Scans

RMF/NIST controls

Policy & Compliance comms

Education

Bachelor's degree in Cybersecurity/IT

Top Secret clearance with SCI eligibility

DoD IAM II/III certifications (CISSP/CISM/CASP+)

DISA ACAS training (preferred)

Tools

eMASS

Xacta

SCC/STIG Viewer

Nessus/Tenable.sc

Job description

Apavo Corporation seeks an Information Systems Security Officer (ISSO) to ensure secure operation of multi-enclave IT/R&D systems across classifications. You will advise system owners on security posture and lead RMF processes using ACAS and DoD tooling to maintain active Authority to Operate without disrupting critical research.

This on-site role in Oakton, VA requires TS eligibility, hands-on ACAS experience, and collaboration with the ISSM and researchers to remediate findings and support