Reference page — cumulative record through Saturday, October 3, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-7273

CVE-2026-7273HIGH

Zyxel GS1900-48HPv2 firmware — A stack-based buffer overflow vulnerability in the CGI program of Zyxel GS1900-48HPv2 firmware versions through 2.90(ABTQ.1)C0 could allo…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   A   L   N   N  U  H  H  H    8.8   .0250   84.2   YES

AFFECTED
  Product                 Versions             Fixed
  GS1900-48HPv2 firmware  <= 2.90(ABTQ.1)C0 –  —
  GS1900-8 firmware       <= 2.90(AAHH.1)C0 –  —
  GS1900-8HP firmware     <= 2.90(AAHI.1)C0 –  —
  GS1900-10HP firmware    <= 2.90(AAZI.1)C0 –  —
  GS1900-16 firmware      <= 2.90(AAHJ.1)C0 –  —
  GS1900-24 firmware      <= 2.90(AAHL.1)C0 –  —
  GS1900-24E firmware     <= 2.90(AAHK.1)C0 –  —
  GS1900-24EP firmware    <= 2.90(ABTO.1)C0 –  —
  GS1900-24HPv2 firmware  <= 2.90(ABTP.1)C0 –  —
  GS1900-48 firmware      <= 2.90(AAHN.1)C0 –  —

TIMELINE
  Apr 28  Reserved by Zyxel
  Jun 16  Published (CNA: Zyxel)
  Sep 21  ADDED TO KEV — CVE-2026-7273 (Zyxel GS1900-48HPv2 firmware). Remediation due September 24, 2026.
  Sep 22  EXPLOIT PUBLISHED — CVE-2026-7273 (Zyxel GS1900-48HPv2 firmware). Public exploit reference added.
  Sep 25  DUE DATE PASSED — CVE-2026-7273 (Zyxel GS1900-48HPv2 firmware). CISA remediation deadline was September 24, 2026; still in catalog.

CWE-121 · CNA: Zyxel · CVSS v3.1 · 3 references · NVD status: Analyzed · KEV due September 24, 2026

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.

Lifecycle

Complete event history — 5 events, chronological
Date	Event	Detail
April 28, 2026	Reserved	Reserved by Zyxel
June 16, 2026	Published	Published (CNA: Zyxel)
September 21, 2026	KEV ADDED	ADDED TO KEV — CVE-2026-7273 (Zyxel GS1900-48HPv2 firmware). Remediation due September 24, 2026.
September 22, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-7273 (Zyxel GS1900-48HPv2 firmware). Public exploit reference added.
September 25, 2026	DUE DATE PASSED	DUE DATE PASSED — CVE-2026-7273 (Zyxel GS1900-48HPv2 firmware). CISA remediation deadline was September 24, 2026; still in catalog.

Affected

Affected products and packages — 10 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
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	—

Weaknesses

CWE-121

References (3)

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-7273 [Third Party Advisory, US Government Resource]
https://www.greynoise.io/blog/open-season-on-kapibala-attacker-steals-government-records-wordpress-exploitation [Exploit, Third Party Advisory]
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 [Vendor Advisory]

Authoritative record: CVE-2026-7273 at cve.org

Vendors: zyxel

Weaknesses: CWE-121

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-7273 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Saturday, October 3, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.