CVE-2026-7273Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability
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.
Overview
Severity
| Score | Severity | Version | Vector String |
|---|---|---|---|
| 8.8 | HIGH | 3.1Zyxel (CNA) | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CISA required action
⚡ Known exploited · remediation due Sep 24, 2026
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Details
- CVE ID
- CVE-2026-7273
- Status
- Analyzed
- Assigner (CNA)
- Zyxel
- Published
- Jun 16, 2026
- Last modified
- 2026-10-25 23:10 UTC
- Weaknesses
- CWE-121 · Stack-based buffer overflow
Affected Products
As published by the CNA in the CVE record.
ZyxelGS1900-48HPv2 firmware1 version range
- <= 2.90(ABTQ.1)C0
ZyxelGS1900-8 firmware1 version range
- <= 2.90(AAHH.1)C0
ZyxelGS1900-8HP firmware1 version range
- <= 2.90(AAHI.1)C0
ZyxelGS1900-10HP firmware1 version range
- <= 2.90(AAZI.1)C0
ZyxelGS1900-16 firmware1 version range
- <= 2.90(AAHJ.1)C0
ZyxelGS1900-24 firmware1 version range
- <= 2.90(AAHL.1)C0
ZyxelGS1900-24E firmware1 version range
- <= 2.90(AAHK.1)C0
ZyxelGS1900-24EP firmware1 version range
- <= 2.90(ABTO.1)C0
ZyxelGS1900-24HPv2 firmware1 version range
- <= 2.90(ABTP.1)C0
ZyxelGS1900-48 firmware1 version range
- <= 2.90(AAHN.1)C0
References
- zyxel.com 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
- cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-7273
- greynoise.io https://www.greynoise.io/blog/open-season-on-kapibala-attacker-steals-government-records-wordpress-exploitation