CVE-2026-7273
Summary
| CVE | CVE-2026-7273 |
|---|---|
| State | PUBLISHED |
| Assigner | Zyxel |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-16 03:16:13 UTC |
| Updated | 2026-09-22 12:10:51 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 8.8 HIGH from [email protected]
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.025010000 probability, percentile 0.841680000 (date 2026-10-03)
CISA KEV: Listed on 2026-09-21; due 2026-09-24; ransomware use Unknown
Problem Types: CWE-121 | CWE-121 CWE-121 Stack-based buffer overflow
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 8.8 | HIGH | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 8.8 | HIGH | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
AdjacentAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA Known Exploited Vulnerability
| Vendor | Zyxel |
|---|---|
| Product | GS1900 Series Switches |
| Name | Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability |
| Required Action | 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. |
| Notes | 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 ; ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-7273 |
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Hardware | Zyxel | Gs1900-10hp | - | All | All | All |
| Operating System | Zyxel | Gs1900-10hp Firmware | All | All | All | All |
| Hardware | Zyxel | Gs1900-16 | - | All | All | All |
| Operating System | Zyxel | Gs1900-16 Firmware | All | All | All | All |
| Hardware | Zyxel | Gs1900-24 | - | All | All | All |
| Hardware | Zyxel | Gs1900-24e | - | All | All | All |
| Hardware | Zyxel | Gs1900-24ep | - | All | All | All |
| Operating System | Zyxel | Gs1900-24ep Firmware | All | All | All | All |
| Operating System | Zyxel | Gs1900-24e Firmware | All | All | All | All |
| Hardware | Zyxel | Gs1900-24hpv2 | - | All | All | All |
| Operating System | Zyxel | Gs1900-24hpv2 Firmware | All | All | All | All |
| Operating System | Zyxel | Gs1900-24 Firmware | All | All | All | All |
| Hardware | Zyxel | Gs1900-48 | - | All | All | All |
| Hardware | Zyxel | Gs1900-48hpv2 | - | All | All | All |
| Operating System | Zyxel | Gs1900-48hpv2 Firmware | All | All | All | All |
| Operating System | Zyxel | Gs1900-48 Firmware | All | All | All | All |
| Hardware | Zyxel | Gs1900-8 | - | All | All | All |
| Hardware | Zyxel | Gs1900-8hp | - | All | All | All |
| Operating System | Zyxel | Gs1900-8hp Firmware | All | All | All | All |
| Operating System | Zyxel | Gs1900-8 Firmware | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Zyxel | GS1900-48HPv2 Firmware | affected <= 2.90(ABTQ.1)C0 | Not specified |
| CNA | Zyxel | GS1900-8 Firmware | affected <= 2.90(AAHH.1)C0 | Not specified |
| CNA | Zyxel | GS1900-8HP Firmware | affected <= 2.90(AAHI.1)C0 | Not specified |
| CNA | Zyxel | GS1900-10HP Firmware | affected <= 2.90(AAZI.1)C0 | Not specified |
| CNA | Zyxel | GS1900-16 Firmware | affected <= 2.90(AAHJ.1)C0 | Not specified |
| CNA | Zyxel | GS1900-24 Firmware | affected <= 2.90(AAHL.1)C0 | Not specified |
| CNA | Zyxel | GS1900-24E Firmware | affected <= 2.90(AAHK.1)C0 | Not specified |
| CNA | Zyxel | GS1900-24EP Firmware | affected <= 2.90(ABTO.1)C0 | Not specified |
| CNA | Zyxel | GS1900-24HPv2 Firmware | affected <= 2.90(ABTP.1)C0 | Not specified |
| CNA | Zyxel | GS1900-48 Firmware | affected <= 2.90(AAHN.1)C0 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.cisa.gov/known-exploited-vulnerabilities-catalog | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | www.cisa.gov | Third Party Advisory, US Government Resource |
| www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory... | [email protected] | www.zyxel.com | Vendor Advisory |
| www.greynoise.io/blog/open-season-on-kapibala-attacker-steals-government-recor... | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | www.greynoise.io | Exploit, Third Party Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
| CISA Known Exploited Vulnerabilities catalog | CISA | www.cisa.gov | kev |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-09-21T00:00:00.000Z | CVE-2026-7273 added to CISA KEV |
There are currently no legacy QID mappings associated with this CVE.