CVE-2026-0413: NETGEAR Router Buffer Overflow Vulnerability

CVE-2026-0413 Overview

CVE-2026-0413 is a buffer overflow vulnerability affecting multiple NETGEAR Orbi mesh router and satellite models. The flaw stems from insufficient input validation in the device's administrative interface. An authenticated administrator on the local network can supply oversized input that overflows a stack buffer, classified as [CWE-121] Stack-based Buffer Overflow. Successful exploitation allows unauthorized modification of router software and functionality. The vulnerability requires both administrative privileges and adjacent network access, limiting its remote exploitability.

Critical Impact
Authenticated administrators on the local network can corrupt the router's stack memory through unvalidated input, enabling unauthorized modification of router software and operational functionality.

Affected Products

NETGEAR Orbi routers including RBE372, RBE770, RBR750, RBR840, RBR850, RBR860, RBRE950, and RBRE960
NETGEAR Orbi satellites including RBS750, RBS840, RBS850, RBS860, RBSE950, and RBSE960
Firmware versions prior to the patches listed in the NETGEAR June 2026 Security Advisory

Discovery Timeline

2026-06-09 - CVE-2026-0413 published to NVD
2026-06-11 - Last updated in NVD database

Technical Details for CVE-2026-0413

Vulnerability Analysis

The vulnerability resides in an input handling routine within the NETGEAR Orbi firmware. The affected code path accepts administrator-supplied data without enforcing length checks before copying it into a fixed-size stack buffer. When the input exceeds the destination buffer size, adjacent stack memory is overwritten, including saved return addresses and local variables.

Because the issue is classified as [CWE-121] Stack-based Buffer Overflow, an attacker can influence control-flow data on the stack. The NETGEAR advisory describes the impact as unauthorized modification of router software and functionality, which is consistent with stack corruption that alters execution paths or configuration data.

The attack surface is constrained. The CVSS 4.0 vector specifies adjacent network access and high privileges required, meaning the attacker must already hold administrative credentials and be connected to the local network or a logically adjacent segment such as a guest VLAN or compromised Wi-Fi client.

Root Cause

The root cause is missing or insufficient bounds checking on attacker-controlled input before it is written into a stack-allocated buffer. The firmware trusts authenticated administrator input and omits length validation prior to the memory copy operation.

Attack Vector

Exploitation requires an attacker to first authenticate as administrator and to be present on the adjacent network. The attacker then submits crafted oversized input to the vulnerable management endpoint, triggering the overflow. No code example is published, and no public proof-of-concept exists. Refer to the NETGEAR Security Advisory June 2026 for vendor-supplied technical context.

Detection Methods for CVE-2026-0413

Indicators of Compromise

Unexpected reboots, crash logs, or watchdog resets on Orbi routers and satellites following administrative sessions
Unauthorized changes to router configuration, firmware images, or administrative settings without a corresponding legitimate change record
Administrative logins from unusual local hosts or at atypical times preceding device instability

Detection Strategies

Monitor administrative HTTP/HTTPS requests to Orbi management interfaces for abnormally large parameter values or malformed payloads
Compare running firmware hashes and configuration baselines against known-good values to detect tampering
Correlate Wi-Fi association logs, DHCP leases, and admin authentication events to identify pre-exploitation reconnaissance

Monitoring Recommendations

Forward router syslog and admin access logs to a centralized logging or SIEM platform for retention and analysis
Alert on repeated authentication failures or successful admin logins from non-management VLANs
Track outbound connections from router management planes for signs of post-exploitation activity

How to Mitigate CVE-2026-0413

Immediate Actions Required

Apply the firmware updates referenced in the NETGEAR Security Advisory June 2026 for each affected Orbi model
Rotate administrator credentials on all Orbi routers and satellites and enforce strong, unique passwords
Restrict administrative access to a dedicated management VLAN and block admin interfaces from guest and IoT networks

Patch Information

NETGEAR has published fixed firmware for the affected Orbi router and satellite models in its June 2026 advisory. Administrators should consult each product's support page for the corresponding patched firmware version, including RBE372, RBE770, RBR750, RBR840, RBR850, RBR860, RBRE950, RBRE960, RBS750, RBS840, RBS850, RBS860, RBSE950, and RBSE960.

Workarounds

Disable remote management and limit the local administrative interface to a trusted management host or subnet
Segment Wi-Fi networks so that untrusted clients cannot reach the router admin interface at Layer 3
Audit and remove unused administrator accounts to reduce the number of identities capable of triggering the flaw

bash

# Configuration example: restrict admin access to a single management host
# Replace 192.0.2.10 with your management workstation IP and run on an upstream firewall
iptables -A FORWARD -p tcp -d <orbi-router-ip> --dport 443 -s 192.0.2.10 -j ACCEPT
iptables -A FORWARD -p tcp -d <orbi-router-ip> --dport 443 -j DROP
iptables -A FORWARD -p tcp -d <orbi-router-ip> --dport 80  -j DROP