Review reviewHigh

CVE-2026-7273

Zyxel GS1900-48HPv2 firmware, GS1900-8 firmware, GS1900-8HP firmware

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.

CVSS: 8.8
EPSS: 0.32%
CISA KEV: Not listed
Published: 2026.06.16

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.32%

Technical severityCVSS 8.8

Vulnerability overview

Affected product and versions

Product: Zyxel GS1900-48HPv2 firmware, GS1900-8 firmware, GS1900-8HP firmware
Affected versions: <= 2.90(ABTQ.1)C0, <= 2.90(AAHH.1)C0, <= 2.90(AAHI.1)C0, <= 2.90(AAZI.1)C0, <= 2.90(AAHJ.1)C0, <= 2.90(AAHL.1)C0, <= 2.90(AAHK.1)C0, <= 2.90(ABTO.1)C0, <= 2.90(ABTP.1)C0, <= 2.90(AAHN.1)C0
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Zyxel GS1900-48HPv2 firmware, GS1900-8 firmware, GS1900-8HP firmware and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

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