CVE-2026-7273 PUBLISHED

Assigner: Zyxel
Reserved: 28.04.2026 Published: 16.06.2026 Updated: 16.06.2026

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.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 8.8

Attack Vector	Adjacent Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	Zyxel
Product	GS1900-48HPv2 firmware
Versions	Default: unaffected Version <= 2.90(ABTQ.1)C0 is affected

Vendor	Zyxel
Product	GS1900-8 firmware
Versions	Default: unaffected Version <= 2.90(AAHH.1)C0 is affected

Vendor	Zyxel
Product	GS1900-8HP firmware
Versions	Default: unaffected Version <= 2.90(AAHI.1)C0 is affected

Vendor	Zyxel
Product	GS1900-10HP firmware
Versions	Default: unaffected Version <= 2.90(AAZI.1)C0 is affected

Vendor	Zyxel
Product	GS1900-16 firmware
Versions	Default: unaffected Version <= 2.90(AAHJ.1)C0 is affected

Vendor	Zyxel
Product	GS1900-24 firmware
Versions	Default: unaffected Version <= 2.90(AAHL.1)C0 is affected

Vendor	Zyxel
Product	GS1900-24E firmware
Versions	Default: unaffected Version <= 2.90(AAHK.1)C0 is affected

Vendor	Zyxel
Product	GS1900-24EP firmware
Versions	Default: unaffected Version <= 2.90(ABTO.1)C0 is affected

Vendor	Zyxel
Product	GS1900-24HPv2 firmware
Versions	Default: unaffected Version <= 2.90(ABTP.1)C0 is affected

Vendor	Zyxel
Product	GS1900-48 firmware
Versions	Default: unaffected Version <= 2.90(AAHN.1)C0 is affected

References

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

Problem Types

CWE-121 Stack-based buffer overflow CWE