CVE-2026-11736 in RAX20
Summary
by MITRE • 08/11/2026
A stack-based buffer overflow vulnerability affects certain NETGEAR models allowing an authenticated admin user to make unauthorized modification to router software and functionality.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability represents a critical stack-based buffer overflow affecting multiple NETGEAR router models that enables authenticated administrative users to execute arbitrary code and modify router firmware functionality. The flaw stems from insufficient input validation within the device's web interface handling mechanisms, specifically when processing user-supplied data in administrative functions. Attackers exploiting this vulnerability can manipulate memory layout through crafted inputs that exceed allocated buffer boundaries, potentially leading to complete system compromise and unauthorized modification of router software components.
The technical implementation of this vulnerability aligns with CWE-121 Stack-based Buffer Overflow, where insufficient bounds checking allows attackers to overwrite adjacent memory locations including return addresses and control data structures. This particular flaw operates within the context of privilege escalation since it requires administrative authentication but ultimately enables attackers to gain deeper system access than initially authorized. The vulnerability exists in the router's web administration interface processing logic where user input is directly handled without proper sanitization or length validation before being copied into fixed-size stack buffers.
From an operational impact perspective, this vulnerability creates significant risk for network infrastructure security as it allows attackers with administrative credentials to modify router firmware and potentially install malicious code that persists across reboots. The affected NETGEAR models likely include popular consumer and small business routers that form the backbone of many home and office networks, making this a widespread concern for organizations relying on these devices. Successful exploitation could result in persistent backdoors, data interception capabilities, or complete network compromise through lateral movement from the compromised router.
The vulnerability's exploitation pattern follows typical attack vectors described in MITRE ATT&CK framework under T1059 Command and Scripting Interpreter and T1547 Persistent Threats, where authenticated access provides a foothold for more sophisticated attacks. Organizations should implement immediate mitigations including firmware updates from NETGEAR, network segmentation to limit administrative access, and monitoring for unusual router configuration changes or firmware modifications. Additionally, security teams should establish baseline configurations and regularly audit router settings to detect unauthorized modifications that may indicate successful exploitation of this vulnerability across affected device models.