{"id":"CVE-2026-7273","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-7273","generatedAt":"2026-10-28T13:11:56.868Z","title":"Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability","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.","published":"2026-06-16T03:16:14.000Z","lastModified":"2026-10-25T23:10:00.000Z","status":"Analyzed","sourceIdentifier":"security@zyxel.com.tw","cvss":{"version":"3.1","score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-121"],"affected":["zyxel/gs1900-8 firmware","zyxel/gs1900-8hp firmware","zyxel/gs1900-10hp firmware","zyxel/gs1900-16 firmware","zyxel/gs1900-24 firmware","zyxel/gs1900-24e firmware","zyxel/gs1900-24ep firmware","zyxel/gs1900-24hpv2 firmware","zyxel/gs1900-48 firmware","zyxel/gs1900-48hpv2 firmware"],"epss":{"score":0.02778,"percentile":0.86298,"date":"2026-10-27","history":[{"date":"2026-09-22","score":0.01987,"percentile":0.7972},{"date":"2026-09-24","score":0.01286,"percentile":0.68864},{"date":"2026-09-26","score":0.02501,"percentile":0.84075}]},"kev":{"listed":true,"dateAdded":"2026-09-21","dueDate":"2026-09-24","knownRansomwareCampaignUse":"Unknown","notes":"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.\nhttps://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"},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"Known to be exploited in the wild (CISA KEV, CISA remediation deadline 24 September 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise."},"changes":[{"kind":"kev","label":"Added to KEV","at":"2026-09-21T00:00:00.000Z","detail":{"name":"Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability","vendor":"Zyxel","dueDate":"2026-09-24","product":"GS1900 Series Switches","ransomware":"Unknown"},"summary":"Added to CISA KEV — known to be exploited; federal remediation due 2026-09-24."}],"references":[{"url":"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","tags":["Vendor Advisory"],"source":"security@zyxel.com.tw"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-7273","tags":["Third Party Advisory","US Government Resource"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://www.greynoise.io/blog/open-season-on-kapibala-attacker-steals-government-records-wordpress-exploitation","tags":["Exploit","Third Party Advisory"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-7273","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}