CVE-2026-7273 KEV
8.8
HIGH · CVSS 3.1 · EPSS 2.5% (pctl 84)
Patch first
On CISA KEV — known exploited in the wild, due 2026-09-24.
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.
Scoring
| CVSS | 8.8 (HIGH, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 2.5% — more likely to be exploited than 84% of all CVEs |
| Weakness | CWE-121 |
| On CISA KEV | yes — remediate by 2026-09-24 |
| Public exploit | none known |
| Published | 2026-06-16 |
| Last modified | 2026-09-22 |
CISA KEV
| Name | Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability |
|---|---|
| Added | 2026-09-21 |
| Due | 2026-09-24 |
| Vendor / product | Zyxel / GS1900 Series Switches |
| Ransomware use | none reported |
Affected (20)
| Vendor | Product |
|---|---|
| zyxel | gs1900-10hp |
| zyxel | gs1900-10hp firmware |
| zyxel | gs1900-16 |
| zyxel | gs1900-16 firmware |
| zyxel | gs1900-24 |
| zyxel | gs1900-24 firmware |
| zyxel | gs1900-24e |
| zyxel | gs1900-24e firmware |
| zyxel | gs1900-24ep |
| zyxel | gs1900-24ep firmware |
| zyxel | gs1900-24hpv2 |
| zyxel | gs1900-24hpv2 firmware |
| zyxel | gs1900-48 |
| zyxel | gs1900-48 firmware |
| zyxel | gs1900-48hpv2 |
| zyxel | gs1900-48hpv2 firmware |
| zyxel | gs1900-8 |
| zyxel | gs1900-8 firmware |
| zyxel | gs1900-8hp |
| zyxel | gs1900-8hp firmware |
References
- 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
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-7273
- https://www.greynoise.io/blog/open-season-on-kapibala-attacker-steals-government-records-wordpress-exploitation
→ the Explorer · watch your stack · NVD