Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability (CVE-2026-7273) is being actively exploited, CISA warns
CISA added CVE-2026-7273 (Zyxel GS1900 Series Switches) to its Known Exploited Vulnerabilities catalog on September 21, 2026, which means there is reliable evidence of exploitation in the wild. 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…
Excerpt from the primary source: CISA Known Exploited Vulnerabilities
Who is affected
Security professionals
Affected technology: GS1900 Series Switches
Why it matters
CISA lists this as exploited in the wild. Unpatched GS1900 Series Switches systems are exposed to active attacks now.
Automated: stated only from CISA listings and the exploitation evidence in the sources below.
What you should do · Patch
Apply the vendor's security update for GS1900 Series Switches. Check the linked advisory for affected and fixed versions, and put internet-facing systems first.
CISA's required action for CVE-2026-7273: "Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines." US federal civilian agencies must comply by September 24, 2026.
Automated guidance based on this story's classification. Check the linked advisories for specifics.
Sources
We link to original and authoritative sources. Headlines and excerpts belong to their publishers.
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