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TI-2026-06387 Aliases CVE-2026-7273GHSA-rrv4-8jq5-8j78

Stack-based buffer overflow in Zyxel GS1900-48HPv2 firmware

Priority CRITICAL 97Exploited in the wildCWE-121Published · Updated

Key facts

Attack vector
Adjacent network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation Active In CISA KEV since 2026-09-21CISA due date 2026-09-24
EPSS 0.02734 86th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Active
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ZyxelGS1900-48HPv2 firmwareup to 2.90(ABTQ.1)C0—No fix listedCNA
ZyxelGS1900-8 firmwareup to 2.90(AAHH.1)C0—No fix listedCNA
ZyxelGS1900-8HP firmwareup to 2.90(AAHI.1)C0—No fix listedCNA
ZyxelGS1900-10HP firmwareup to 2.90(AAZI.1)C0—No fix listedCNA
ZyxelGS1900-16 firmwareup to 2.90(AAHJ.1)C0—No fix listedCNA
ZyxelGS1900-24 firmwareup to 2.90(AAHL.1)C0—No fix listedCNA
ZyxelGS1900-24E firmwareup to 2.90(AAHK.1)C0—No fix listedCNA
ZyxelGS1900-24EP firmwareup to 2.90(ABTO.1)C0—No fix listedCNA
ZyxelGS1900-24HPv2 firmwareup to 2.90(ABTP.1)C0—No fix listedCNA
ZyxelGS1900-48 firmwareup to 2.90(AAHN.1)C0—No fix listedCNA
  • GS1900-48HPv2 firmware VendorZyxel Affected up to 2.90(ABTQ.1)C0 Fixed in — No fix listed CNA
  • GS1900-8 firmware VendorZyxel Affected up to 2.90(AAHH.1)C0 Fixed in — No fix listed CNA
  • GS1900-8HP firmware VendorZyxel Affected up to 2.90(AAHI.1)C0 Fixed in — No fix listed CNA
  • GS1900-10HP firmware VendorZyxel Affected up to 2.90(AAZI.1)C0 Fixed in — No fix listed CNA
  • GS1900-16 firmware VendorZyxel Affected up to 2.90(AAHJ.1)C0 Fixed in — No fix listed CNA
  • GS1900-24 firmware VendorZyxel Affected up to 2.90(AAHL.1)C0 Fixed in — No fix listed CNA
  • GS1900-24E firmware VendorZyxel Affected up to 2.90(AAHK.1)C0 Fixed in — No fix listed CNA
  • GS1900-24EP firmware VendorZyxel Affected up to 2.90(ABTO.1)C0 Fixed in — No fix listed CNA
  • GS1900-24HPv2 firmware VendorZyxel Affected up to 2.90(ABTP.1)C0 Fixed in — No fix listed CNA
  • GS1900-48 firmware VendorZyxel Affected up to 2.90(AAHN.1)C0 Fixed in — No fix listed CNA

CPE configurations NVD · 20

CPEVersionsRoleVendor
cpe:2.3:o:zyxel:gs1900-8_firmware:*:*:*:*:*:*:*:*before 2.90\(aahh.2\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-8:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-8hp_firmware:*:*:*:*:*:*:*:*before 2.90\(aahi.2\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-8hp:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-10hp_firmware:*:*:*:*:*:*:*:*before 2.90\(aazi.2\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-10hp:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-16_firmware:*:*:*:*:*:*:*:*before 2.90\(aahj.2\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-16:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-24_firmware:*:*:*:*:*:*:*:*before 2.90\(aahl.2\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-24:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
  • cpe:2.3:o:zyxel:gs1900-8_firmware:*:*:*:*:*:*:*:* Versions before 2.90\(aahh.2\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-8:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-8hp_firmware:*:*:*:*:*:*:*:* Versions before 2.90\(aahi.2\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-8hp:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-10hp_firmware:*:*:*:*:*:*:*:* Versions before 2.90\(aazi.2\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-10hp:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-16_firmware:*:*:*:*:*:*:*:* Versions before 2.90\(aahj.2\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-16:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-24_firmware:*:*:*:*:*:*:*:* Versions before 2.90\(aahl.2\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-24:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
Show 10 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:zyxel:gs1900-24e_firmware:*:*:*:*:*:*:*:*before 2.90\(aahk.2\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-24e:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-24ep_firmware:*:*:*:*:*:*:*:*before 2.90\(abto.2\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-24ep:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-24hpv2_firmware:*:*:*:*:*:*:*:*before 2.90\(abtp.2\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-24hpv2:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-48_firmware:*:*:*:*:*:*:*:*before 2.90\(aahn.2\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-48:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:gs1900-48hpv2_firmware:*:*:*:*:*:*:*:*before 2.90\(abtq.2\)c0VulnerableZyxel
cpe:2.3:h:zyxel:gs1900-48hpv2:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
  • cpe:2.3:o:zyxel:gs1900-24e_firmware:*:*:*:*:*:*:*:* Versions before 2.90\(aahk.2\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-24e:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-24ep_firmware:*:*:*:*:*:*:*:* Versions before 2.90\(abto.2\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-24ep:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-24hpv2_firmware:*:*:*:*:*:*:*:* Versions before 2.90\(abtp.2\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-24hpv2:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-48_firmware:*:*:*:*:*:*:*:* Versions before 2.90\(aahn.2\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-48:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:gs1900-48hpv2_firmware:*:*:*:*:*:*:*:* Versions before 2.90\(abtq.2\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:gs1900-48hpv2:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-09-21 Added to CISA KEV
  2. 2026-10-02 Threatist record created from CVE-2026-7273
  3. 2026-10-03 Alias added: GHSA-rrv4-8jq5-8j78

References

Exploit 1

Advisory 2

  • TI-2019-11869 An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. CVSS 3.1CRITICAL 9.8
  • TI-2016-01221 Cisco NX-OS 6.0(2)U6(1) through 6.0(2)U6(5) on Nexus 3000 devices and 6.0(2)A6(1) through… CVSS 3.0CRITICAL 9.8
  • TI-2015-05062 Belkin F9K1102 2 devices with firmware 2.10.17 rely on client-side JavaScript code for… CVSS 3.0CRITICAL 9.8
  • TI-2015-05061 The web management interface on Belkin F9K1102 2 devices with firmware 2.10.17 has a… CVSS 3.0CRITICAL 9.8
  • TI-2019-11872 An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. CVSS 3.1CRITICAL 9.1
  • TI-2019-11868 An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. CVSS 3.1HIGH 8.8
See all 34 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences