MSRXCVE-2026-7273
CVE-2026-7273
Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability
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.
CVSS 3.1 · CNA · zyxel.com.tw
chance of exploitation in the next 30 days (EPSS; higher than 86% of CVEs)
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.
Scores
Affected products
- zyxel gs1900-8 firmware: < 2.90\(aahh.2\)c0
- zyxel gs1900-8hp firmware: < 2.90\(aahi.2\)c0
- zyxel gs1900-10hp firmware: < 2.90\(aazi.2\)c0
- zyxel gs1900-16 firmware: < 2.90\(aahj.2\)c0
- zyxel gs1900-24 firmware: < 2.90\(aahl.2\)c0
- zyxel gs1900-24e firmware: < 2.90\(aahk.2\)c0
- zyxel gs1900-24ep firmware: < 2.90\(abto.2\)c0
- zyxel gs1900-24hpv2 firmware: < 2.90\(abtp.2\)c0
- zyxel gs1900-48 firmware: < 2.90\(aahn.2\)c0
- zyxel gs1900-48hpv2 firmware: < 2.90\(abtq.2\)c0
Weakness: CWE-121
3 references (advisories, patches, write-ups)
- 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
- 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
Sources: NVD, CVE.org, FIRST EPSS. Missing ones did not answer or have no record yet.