Description
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 products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Zyxel GS1900-48HPv2 firmware
Default version status: unaffected
<= 2.90(ABTQ.1)C0affected
Zyxel GS1900-8 firmware
Default version status: unaffected
<= 2.90(AAHH.1)C0affected
Zyxel GS1900-8HP firmware
Default version status: unaffected
<= 2.90(AAHI.1)C0affected
Zyxel GS1900-10HP firmware
Default version status: unaffected
<= 2.90(AAZI.1)C0affected
Zyxel GS1900-16 firmware
Default version status: unaffected
<= 2.90(AAHJ.1)C0affected
Zyxel GS1900-24 firmware
Default version status: unaffected
<= 2.90(AAHL.1)C0affected
Zyxel GS1900-24E firmware
Default version status: unaffected
<= 2.90(AAHK.1)C0affected
Zyxel GS1900-24EP firmware
Default version status: unaffected
<= 2.90(ABTO.1)C0affected
Zyxel GS1900-24HPv2 firmware
Default version status: unaffected
<= 2.90(ABTP.1)C0affected
Zyxel GS1900-48 firmware
Default version status: unaffected
<= 2.90(AAHN.1)C0affected
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.greynoise.io/blog/open-season-on-kapibala-attacker-steals-government-records-wordpress-exploitation ↗
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-7273 ↗