Senior Information System Security Officer (ISSO)

Job Title: Senior Information System Security Officer (ISSO)

Security Clearance: Ability to Obtain Tier 4 High-Risk Public Trust

Location: Washington, D.C.

(Due to the nature of the work and contract requirements, U.S. Citizenship is required.)

C3EL is seeking a Senior Information System Security Officer (ISSO) to provide on-site cybersecurity and Risk Management Framework (RMF) sustainment support in Washington, D.C., for a new contract. This role will serve as Operational Specialist for Splunk, ServiceNow, ConMon, vulnerability management, POA&M, and incident and change coordination, as well as being workstream lead and secondary backup for Lead ISSO duties.

Responsibilities will include, but not be limited to:

• Provide on-site cybersecurity and RMF sustainment support.
• Maintain traceability between ServiceNow remediation tickets and CSAM POA&M records.
• Analyze findings, validate false positives, and prioritize remediation using CVSS, CISA KEV, exposure, exploitability, and mission impact.
• Support notification, triage, CSAM context retrieval, Splunk verification, SitReps, RCA, corrective actions, and post-incident updates.
• Support CAB/CCB/ERB reviews, security impact analysis, artifact updates, and post-change verification.
• Track audit, penetration-test, and assessment findings through corrective action and evidence-supported closure.
• Maintain incident-response plans and support tabletop or functional exercises.
• Produce accurate, concise, and audit-ready Government cybersecurity documentation.
• Support team coverage from 7:00 a.m. to 6:00 p.m. ET (M-F) and participate in after-hours incident coverage as needed.

Minimum Qualifications:

• U.S. Citizenship.
• Eligibility to obtain a Tier 4 High-Risk Public Trust.
• Minimum seven (7) years of cybersecurity.
• Minimum five (5) years in federal ISSO, ConMon, vulnerability, security operations, or compliance work.
• Working knowledge of NIST SP 800-37, 800-53, 800-53B, FIPS 199, FISMA, and applicable CISA/OMB guidance.
• Familiarity with GRC, ITSM, SIEM, scanner, identity, endpoint, and cloud-security platforms.
• Direct experience with Splunk searches, dashboards, ingestion verification, log coverage, and incident timeline support.
• Direct experience with ServiceNow incidents, problems, changes, remediation tickets, and reporting.
• Direct experience with Tenable Nessus, Qualys, ACAS, or comparable Government-approved scanners.
• Experience with Defender, Intune, BigFix, or equivalent endpoint and configuration platforms.

Preferred Qualifications:

• At least one current cybersecurity certification such as CISSP, CGRC, CISM, CRISC, Security+, SecurityX, CCSP, or GIAC.