# CVE-2026-7273: Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability

> CVE-2026-7273: Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability. CVSS 8.8 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2026-7273
Last updated: 2026-09-22T12:10:51Z

- Published: 2026-06-16 02:20 UTC · Updated: 2026-09-22 12:10 UTC · Assigner: Zyxel
- CVSS: 8.8 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS: 2.8%, 86th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2026-09-21, federal due date 2026-09-24, ransomware use: Unknown
- CWE: CWE-121

## 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.

## CISA required action

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.

## Affected vendors and products

- Zyxel: GS1900-10HP firmware
- Zyxel: GS1900-16 firmware
- Zyxel: GS1900-24E firmware
- Zyxel: GS1900-24EP firmware
- Zyxel: GS1900-24 firmware
- Zyxel: GS1900-24HPv2 firmware
- Zyxel: GS1900-48 firmware
- Zyxel: GS1900-48HPv2 firmware
- Zyxel: GS1900-8 firmware
- Zyxel: GS1900-8HP firmware

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-7273)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-7273)
- [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.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-stack-based-buffer-overflow-vulnerability-in-gs1900-series-switches-06-16-2026)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-7273 · Markdown: https://rewindex.com/cve/CVE-2026-7273.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-7273 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:01:37.479Z