CVE-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.

Affected

Zyxel · GS1900-48HPv2 firmware · GS1900-8 firmware · GS1900-8HP firmware · GS1900-10HP firmware · GS1900-16 firmware · GS1900-24 firmware

CVSS v3.1 ZYXEL

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

EPSS

2.50% chance of exploitation in the next 30 days, 84th percentile

CISA KEV

added 2026-09-21

Published

2026-06-16

Updated

2026-09-22

Proof-of-concept exploits (1)

• https://www.greynoise.io/blog/open-season-on-kapibala-attacker-steals-government-records-…

Security advisories

• https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-s…
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-7273

References

• CVE Record
• NVD entry