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.

CVSS 3.1

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

EPSS

2.8% chance of exploitation in the next 30 days; higher than 86% of CVEs (scores of 2026-10-25)

CISA KEV

listed 2026-09-21, due 2026-09-24

CWE

CWE-121

Published

2026-06-16

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

Affected

• zyxel:gs1900-10hp_firmware
• zyxel:gs1900-16_firmware
• zyxel:gs1900-24_firmware
• zyxel:gs1900-24e_firmware
• zyxel:gs1900-24ep_firmware
• zyxel:gs1900-24hpv2_firmware
• zyxel:gs1900-48_firmware
• zyxel:gs1900-48hpv2_firmware
• zyxel:gs1900-8_firmware
• zyxel:gs1900-8hp_firmware

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
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-7273
• https://www.greynoise.io/blog/open-season-on-kapibala-attacker-steals-government-records-wordpress-exploitation

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