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Findings

CVE-2026-7273

Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability

Published Jun 15, 2026 · updated Sep 22, 2026 · Zyxel GS1900 Series Switches

A stack-based buffer overflow vulnerability in the CGI program of Zyxel GS1900-48HPv2 firmware versions through 2.90(ABTQ.1)C0 could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request.

Timeline

Detection, updates, and resolution for this record.

  1. Jun 15, 2026 · Catalog

    Detected

    A stack-based buffer overflow vulnerability in the CGI program of Zyxel GS1900-48HPv2 firmware versions through 2.90(ABTQ.1)C0 could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request.

  2. Sep 21, 2026 · CISA KEV

    Known exploited

    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

  3. Sep 22, 2026 · Catalog

    Updated

    A stack-based buffer overflow vulnerability in the CGI program of Zyxel GS1900-48HPv2 firmware versions through 2.90(ABTQ.1)C0 could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request.

  4. Sep 24, 2026 · CISA KEV

    Remediation due

    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

Required action

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.

CISA due date Sep 24, 2026

Affected

  • cpe zyxel/gs1900-10hp firmwareversion unspecified
  • cpe zyxel/gs1900-16 firmwareversion unspecified
  • cpe zyxel/gs1900-24 firmwareversion unspecified
  • cpe zyxel/gs1900-24e firmwareversion unspecified
  • cpe zyxel/gs1900-24ep firmwareversion unspecified
  • cpe zyxel/gs1900-24hpv2 firmwareversion unspecified
  • cpe zyxel/gs1900-48 firmwareversion unspecified
  • cpe zyxel/gs1900-48hpv2 firmwareversion unspecified
  • cpe zyxel/gs1900-8 firmwareversion unspecified
  • cpe zyxel/gs1900-8hp firmwareversion unspecified
  • vendor Zyxel GS1900 Series Switchesversion unspecified

Sources

  • CISA KEVCVE-2026-7273

    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.

    cisa.gov
  • CVE.orgCVE-2026-7273

    Official CVE identifier

    cve.org
  • FIRST EPSSCVE-2026-7273

    30-day exploitation probability 2.5%

    first.org
  • NIST NVDCVE-2026-7273

    A stack-based buffer overflow vulnerability in the CGI program of Zyxel GS1900-48HPv2 firmware versions through 2.90(ABTQ.1)C0 could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request.

    nvd.nist.gov

References