Senior Information System Security Officer (ISSO)
- Location
- Washington, D.C.
- Work mode
- On-site
- Employment type
- Full-time
About the job
**CONTINGENT UPON CONTRACT AWARD**
Overview:
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. )
Description:
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.
Education:
- Associate’s degree in Cybersecurity, Information Technology, or related field. (Relevant experience may be considered in lieu of formal education.)
From C3EL's careers page (Greenhouse), checked 29 Oct 2026.
How to apply
- Select Apply on job-boards.greenhouse.io. It opens C3EL's own application form in a new tab, run on Greenhouse.
- Fill in the form and upload your résumé there. Jobiwork never sees your application.
- C3EL will reply to you directly. No real employer asks you for money to apply.
Posted 2 Sept 2026 · checked 29 Oct 2026 · Report this job