---
title: "Senior Information System Security Officer (ISSO)"
company: "C3EL"
company_url: "https://www.remjobs.works/companies/c3el"
url: "https://www.remjobs.works/job/c3el-senior-information-system-security-officer-isso-449609c9-9c41-4845-8f5c-c7c5bf650481"
apply_url: "https://job-boards.greenhouse.io/c3el/jobs/5225490007"
workplace: onsite
location: "Washington, D.C."
employment_type: unspecified
seniority: senior
role: devops-infrastructure
region: united-states
date_posted: 2026-09-02T21:14:26.000Z
first_seen_by_remjobs: 2026-09-15T19:02:51.992Z
---

# Senior Information System Security Officer (ISSO)

**C3EL** · Washington, D.C.

Apply: https://job-boards.greenhouse.io/c3el/jobs/5225490007

## About the role

##### **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.)

---

Source: C3EL's own career page, read by RemJobs. Canonical HTML version: https://www.remjobs.works/job/c3el-senior-information-system-security-officer-isso-449609c9-9c41-4845-8f5c-c7c5bf650481