{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/vendors/zyxel/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["4G LTE/5G NR CPE","DSL/Ethernet CPE","Fiber ONTs","Wireless Extenders"],"_cs_severities":["high"],"_cs_tags":["command injection","network device","vulnerability"],"_cs_type":"advisory","_cs_vendors":["Zyxel"],"content_html":"\u003cp\u003eOn April 28, 2026, Zyxel issued a security advisory (AV26-399) detailing command injection vulnerabilities present in several of their customer premise equipment (CPE) and wireless extender product lines. The affected products include 4G LTE/5G NR CPE, DSL/Ethernet CPE, Fiber ONTs, and Wireless Extenders. The advisory urges users and administrators to promptly review the provided web links and apply the necessary updates to mitigate the risk of exploitation. Successful exploitation of these vulnerabilities could enable attackers to execute arbitrary commands on the affected devices, potentially leading to unauthorized access, device compromise, and network disruption. Due to the widespread use of these devices, particularly in home and small business environments, the potential impact is significant.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker identifies a vulnerable Zyxel device with an exposed management interface.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP request containing a command injection payload within a vulnerable parameter.\u003c/li\u003e\n\u003cli\u003eThe request is sent to the Zyxel device through the web management interface.\u003c/li\u003e\n\u003cli\u003eThe device processes the request and inadvertently executes the injected command due to insufficient input validation.\u003c/li\u003e\n\u003cli\u003eThe attacker gains arbitrary command execution on the device\u0026rsquo;s operating system.\u003c/li\u003e\n\u003cli\u003eThe attacker uses the compromised device to pivot further into the network.\u003c/li\u003e\n\u003cli\u003eThe attacker may install malware or create a reverse shell for persistent access.\u003c/li\u003e\n\u003cli\u003eThe attacker compromises other devices or exfiltrates sensitive data from the network.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of these command injection vulnerabilities could allow attackers to gain complete control over the affected Zyxel devices. This could lead to unauthorized access to the network, modification of device configurations, and potential data breaches. Given the ubiquity of these Zyxel products, a large number of users and organizations are potentially at risk. The impact could range from disruption of internet services to full network compromise and data theft.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eReview the Zyxel security advisory (\u003ca href=\"https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-command-injection-vulnerabilities-in-certain-4g-lte-5g-nr-cpe-dsl-ethernet-cpe-fiber-onts-and-wireless-extenders-04-28-2026\"\u003ehttps://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-command-injection-vulnerabilities-in-certain-4g-lte-5g-nr-cpe-dsl-ethernet-cpe-fiber-onts-and-wireless-extenders-04-28-2026\u003c/a\u003e) to identify affected devices and specific vulnerabilities.\u003c/li\u003e\n\u003cli\u003eApply the recommended firmware updates provided by Zyxel to patch the command injection vulnerabilities.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for suspicious HTTP requests containing command injection attempts targeting Zyxel devices by deploying the \u0026ldquo;Detect Zyxel Command Injection Attempt\u0026rdquo; Sigma rule.\u003c/li\u003e\n\u003cli\u003eImplement network segmentation to limit the impact of a potential device compromise.\u003c/li\u003e\n\u003cli\u003eRegularly review and update device configurations to ensure strong passwords and disable unnecessary services.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-29T12:00:00Z","date_published":"2026-04-29T12:00:00Z","id":"/briefs/2026-04-zyxel-command-injection/","summary":"Zyxel released a security advisory on April 28, 2026, addressing command injection vulnerabilities across multiple versions of their 4G LTE/5G NR CPE, DSL/Ethernet CPE, Fiber ONTs, and Wireless Extender products, potentially allowing attackers to execute arbitrary commands.","title":"Zyxel Command Injection Vulnerabilities in CPE and Extenders","url":"https://feed.craftedsignal.io/briefs/2026-04-zyxel-command-injection/"}],"language":"en","title":"CraftedSignal Threat Feed — Zyxel","version":"https://jsonfeed.org/version/1.1"}