CVE-2026-7273
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.
Actively exploited
- In the CISA exploited-vulnerabilities catalogue since Sep 21, 2026
- US federal agencies must remediate it by Sep 24, 2026 (BOD 22-01)
- First attack observed 97 days after disclosure
- Confirmed by sensors, not only by reports
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.
Source: CISA KEV · Sep 21, 2026 Sep 21, 2026
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HAffected products
| Vendors | Product | Versions |
|---|---|---|
| zyxel | gs1900-8 firmware | < 2.90\(aahh.2\)c0 |
| zyxel | gs1900-8 | - |
| zyxel | gs1900-8hp firmware | < 2.90\(aahi.2\)c0 |
| zyxel | gs1900-8hp | - |
| zyxel | gs1900-10hp firmware | < 2.90\(aazi.2\)c0 |
| zyxel | gs1900-10hp | - |
| zyxel | gs1900-16 firmware | < 2.90\(aahj.2\)c0 |
| zyxel | gs1900-16 | - |
| zyxel | gs1900-24 firmware | < 2.90\(aahl.2\)c0 |
| zyxel | gs1900-24 | - |
| zyxel | gs1900-24e firmware | < 2.90\(aahk.2\)c0 |
| zyxel | gs1900-24e | - |
| zyxel | gs1900-24ep firmware | < 2.90\(abto.2\)c0 |
| zyxel | gs1900-24ep | - |
| zyxel | gs1900-24hpv2 firmware | < 2.90\(abtp.2\)c0 |
| zyxel | gs1900-24hpv2 | - |
| zyxel | gs1900-48 firmware | < 2.90\(aahn.2\)c0 |
| zyxel | gs1900-48 | - |
| zyxel | gs1900-48hpv2 firmware | < 2.90\(abtq.2\)c0 |
| zyxel | gs1900-48hpv2 | - |
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