CVE-2026-7273

What it is

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.

At a glance

Exploitability

Can be exploited from the same network segment without logging in. High risk of data exposure, data tampering, service disruption.

In the wild

CISA lists this as exploited in real attacks. Treat as urgent.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-04-28 06:21 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-06-16 03:16 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-09-21 Exploited in the wildAdded to CISA's Known Exploited Vulnerabilities list
4. 2026-09-24 Remediation deadlineCISA's due date for federal agencies to fix it
5. 2026-10-25 23:10 UTC Last updatedMost recent change to the record

Details

Published

2026-06-16 03:16 UTC

Last modified

2026-10-25 23:10 UTC

Added to CISA KEV

2026-09-21

Exploit probability

2.8% · EPSS, next 30 days

Weakness

CWE-121

Record status

Analyzed

Affected

• Zyxel gs1900-8 Firmware < 2.90\(aahh.2\)c0
• Zyxel gs1900-8hp Firmware < 2.90\(aahi.2\)c0
• Zyxel gs1900-10hp Firmware < 2.90\(aazi.2\)c0
• Zyxel gs1900-16 Firmware < 2.90\(aahj.2\)c0
• Zyxel gs1900-24 Firmware < 2.90\(aahl.2\)c0
• Zyxel gs1900-24e Firmware < 2.90\(aahk.2\)c0
• Zyxel gs1900-24ep Firmware < 2.90\(abto.2\)c0
• Zyxel gs1900-24hpv2 Firmware < 2.90\(abtp.2\)c0

Attack profile CVSS 3.1 · 8.8

Attack vector

Adjacent network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High