Actively exploited · Published Jun 16, 2026 · Assigned by Zyxel

CVE-2026-7273

High 8.8 Exploited

In plain English

A high-severity stack buffer overflow in GS1900-10HP firmware from Zyxel. Attackers are actively exploiting it in the wild (listed by CISA on September 21, 2026). The chance it is exploited in the next 30 days is estimated at 2.7% (higher than 86% of all known vulnerabilities). 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.

Severity (CVSS 3.1)8.8High
Exploit odds (30 days)2.7%top 13.8% of all CVEs
Exploited in the wildYesCISA KEV since Sep 21, 2026
Attack toolingNoneno public tooling known

CISA guidance

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.

Federal agencies must remediate by Sep 24, 2026.

Official 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 (as reported)

VendorProductVersions
Zyxel GS1900-48HPv2 firmware <= 2.90(ABTQ.1)C0
Zyxel GS1900-8 firmware <= 2.90(AAHH.1)C0
Zyxel GS1900-8HP firmware <= 2.90(AAHI.1)C0
Zyxel GS1900-10HP firmware <= 2.90(AAZI.1)C0
Zyxel GS1900-16 firmware <= 2.90(AAHJ.1)C0
Zyxel GS1900-24 firmware <= 2.90(AAHL.1)C0
Zyxel GS1900-24E firmware <= 2.90(AAHK.1)C0
Zyxel GS1900-24EP firmware <= 2.90(ABTO.1)C0
Zyxel GS1900-24HPv2 firmware <= 2.90(ABTP.1)C0
Zyxel GS1900-48 firmware <= 2.90(AAHN.1)C0

Weakness: CWE-121 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References