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PatchSiren cyber security CVE debrief

CVE-2026-7273 Zyxel CVE debrief

CVE-2026-7273 is a stack-based buffer overflow vulnerability in the CGI program of Zyxel GS1900-48HPv2 firmware versions through 2.90(ABTQ.1)C0. This vulnerability could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request. The vulnerability has a CVSS score of 8.8 and is classified as HIGH severity.

Vendor
Zyxel
Product
GS1900-48HPv2 firmware
CVSS
HIGH 8.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-16
Original CVE updated
2026-06-18
Advisory published
2026-06-16
Advisory updated
2026-06-18

Who should care

Administrators and users of Zyxel GS1900-48HPv2 switches, especially those with firmware versions through 2.90(ABTQ.1)C0, should be aware of this vulnerability and take necessary actions to mitigate the risk.

Technical summary

The vulnerability is caused by a stack-based buffer overflow in the CGI program of the affected device. This could allow an attacker to execute OS commands via a crafted HTTP request.

Defensive priority

HIGH

Recommended defensive actions

  • Apply the patch or update to a fixed firmware version as recommended by the vendor.
  • Restrict access to the affected device to only trusted networks and users.
  • Monitor the device for suspicious activity.

Evidence notes

The CVE record and NVD detail pages provide evidence of this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-7273 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-7273

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-7273 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-7273

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-stack-based-buffer-overflow-vulnerability-in-gs1900-series-switches-06-16-2026

    [email protected]

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.