CVE-2026-7273 - Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability (known exploited)
Added to CISA KEV on 2026-09-21. Zyxel GS1900 series switches contain a stack-based buffer overflow vulnerability in the CGI program which could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request.
CRITICAL
CISA KEV
ACTIVELY EXPLOITED
Severity & confidence
Source severitycritical
Platform severitycritical
Confidencehigh
Exploitationactively exploited
CVSS-
Affected
ProductsGS1900 Series Switches
Reporting sources (2)
CISA - Known Exploited Vulnerabilities
CISA - Cybersecurity Advisories
๐ฏ Why should I care?
- On the CISA Known Exploited Vulnerabilities list.
- Credible sources report active exploitation in the wild.
Timeline & provenance
Published2026-09-21T00:00:00
Last updated2026-10-21T04:58:06
Ingested2026-09-21T19:43:44
FreshnessNEAR-REAL-TIME
Threat typeexploitation
Recommended action
Apply the vendor-supplied patch immediately. Review vendor and CISA guidance for detection and mitigation.
Next steps
- Identify affected systems in your environment.
- Apply the vendor patch or mitigation guidance.
- Review logs for indicators described in the advisory.
- Follow the affected vendor/product to track updates.
Confidence explanation
Reported by a government or cert-grade source (CISA, NCSC, NVD, ENISA, MSRC).
Source type: gov ยท Original: CISA - Known Exploited Vulnerabilities
