CISA Adds Zyxel GS1900 Command Execution Flaw to KEV
Tech GuruQuick Answer
The authority published CISA KEV: CVE-2026-7273 for Zyxel GS1900-8, -8HP, -10HP, -16, -24, -24E, -24EP, -24HPv2, -48, and -48HPv2 switches. CISA added CVE-2026-7273 to the Known Exploited Vulnerabilities Catalog and requires federal remediation by September 24, 2026; Zyxel provides model-specific patched firmware. Affected deployments should be matched to the authority's exact scope and moved to the supported fixed release.
Confirm Scope And Apply The Supported Fix
What to do now: Inventory Zyxel GS1900-8, -8HP, -10HP, -16, -24, -24E, -24EP, -24HPv2, -48, and -48HPv2 switches, match the exact affected release or feature, apply the authority-supported fixed build or service remediation, validate the dependent workflow, and preserve evidence.
Last verified: 2026-09-22 UTC. Recheck the authoritative advisory and supported distribution channel before changing production.
Scope And Authority
| Product scope | Zyxel GS1900-8, -8HP, -10HP, -16, -24, -24E, -24EP, -24HPv2, -48, and -48HPv2 switches |
|---|---|
| Advisory | CISA KEV: CVE-2026-7273 |
| CVE | CVE-2026-7273 |
| Authoritative release date | 2026-09-21 18:46:35.087300 UTC |
| Authority revision date | 2026-09-21 18:46:35.087300 UTC |
| Affected versions | The listed GS1900 models at firmware 2.90(*.1)C0 and earlier, using each model's Zyxel firmware code; the attack is LAN-based and unauthenticated. |
| Fixed version | Each listed model's Zyxel firmware 2.90(*.2)C0 release |
| CVSS base score | Not provided by the authority |
| CVSS severity | Not provided by the authority |
| Exploitation status | Known exploited: CISA added CVE-2026-7273 to the KEV Catalog on 2026-09-21; ransomware use is listed as Unknown; no exploitation claim is inferred. |
What Changed
CISA added CVE-2026-7273 to the Known Exploited Vulnerabilities Catalog and requires federal remediation by September 24, 2026; Zyxel provides model-specific patched firmware.
What To Validate Now
- Inventory. Locate Zyxel GS1900-8, -8HP, -10HP, -16, -24, -24E, -24EP, -24HPv2, -48, and -48HPv2 switches deployments, versions, enabled features, exposure paths, owners, and dependent services.
- Establish applicability. Compare each deployment with the authority's affected-version statement: The listed GS1900 models at firmware 2.90(*.1)C0 and earlier, using each model's Zyxel firmware code; the attack is LAN-based and unauthenticated. Do not infer applicability from product family or severity alone.
- Remediate. Apply Each listed model's Zyxel firmware 2.90(*.2)C0 release through the supported vendor or project channel, following the current advisory and change-control requirements.
- Validate. Confirm the resulting version or managed-service state, exercise representative functionality and recovery paths, monitor for regressions, and document exceptions.
- Retain evidence. Preserve asset and owner identifiers, the applicability decision, before-and-after versions, change approval, installation output, validation results, and any exception or rollback record.
Operational Cautions
Use the exact supported release stream and repository. Test dependencies, clusters, integrations, and rollback before broad deployment; a CVSS rating or reachable feature is not evidence of exploitation.
Evidence To Retain
- Exact product, release stream, package or application version, enabled feature, environment, and accountable owner.
- UTC timestamps, authority revision, approved change record, installer or package-manager output, and resulting version.
- Relevant logs and monitoring evidence, test results, exceptions, compensating controls, and rollback decisions.
Related TechGeeks Resources
Authoritative References
Correction policy: If the authority changes affected versions, fixed versions, severity, exploitation information, mitigations, or required action, TechGeeks will update this notice and its verification date.
