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.

Official resources

CVE-2026-7273 was published on 2026-06-16T03:16:13.557Z and has not been modified since then.