CVE-2026-0402 in SonicOS
Summary
by MITRE • 02/24/2026
A post-authentication Out-of-bounds Read vulnerability in SonicOS allows a remote attacker to crash a firewall.
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Analysis
by VulDB Data Team • 02/28/2026
The vulnerability identified as CVE-2026-0402 represents a critical post-authentication out-of-bounds read flaw within SonicOS firmware, which powers SonicWall firewalls widely deployed in enterprise environments. This vulnerability specifically affects the operating system component responsible for processing network traffic and firewall rules, creating a significant security risk for organizations relying on SonicWall hardware for network protection. The issue manifests as an improper bounds checking mechanism within the firewall's memory management system, where insufficient validation occurs when processing certain network packets or configuration data. According to CWE-129, this vulnerability stems from inadequate input validation that allows an attacker to manipulate memory access patterns beyond allocated buffer boundaries. The flaw exists in the firmware's packet processing pipeline, where network data is parsed and validated before being applied to firewall policies, creating an exploitable condition that can be triggered through crafted network traffic.
The operational impact of this vulnerability extends beyond simple service disruption, as it enables remote attackers to execute controlled crashes against firewall systems without requiring administrative credentials for initial access. This post-authentication nature means that even users with limited privileges can potentially exploit the vulnerability, though they must first establish a valid authentication session to the firewall's management interface. The out-of-bounds read condition can cause memory corruption that leads to system instability and potential denial of service scenarios, effectively compromising network security by disabling the very protection mechanisms meant to safeguard the organization. Attackers leveraging this vulnerability can disrupt network connectivity for extended periods, potentially allowing lateral movement within the network or enabling more sophisticated attacks that exploit the temporary firewall unavailability. From an ATT&CK framework perspective, this vulnerability maps to T1499.004 (Network Denial of Service) and T1566.001 (Phishing via Social Engineering) as it can be part of broader attack chains where initial access is gained through social engineering or other means, followed by service disruption.
Mitigation strategies for CVE-2026-0402 should prioritize immediate firmware updates from SonicWall, as the vendor has likely released patches addressing the specific bounds checking issues within the memory management components. Organizations should implement network segmentation to limit exposure and ensure that firewall management interfaces are not directly accessible from untrusted networks. Additionally, monitoring systems should be configured to detect unusual traffic patterns or service disruptions that might indicate exploitation attempts. Security teams must also consider implementing intrusion detection systems that can identify crafted packets designed to trigger the out-of-bounds read condition. The vulnerability demonstrates the importance of robust input validation and memory safety practices, as outlined in the CWE guidelines for preventing buffer overflow conditions. Organizations should conduct comprehensive vulnerability assessments to identify other potential memory corruption issues within their firewall infrastructure and ensure that security patches are applied promptly across all network security devices. Regular security audits of firmware components and implementation of network monitoring solutions can help detect exploitation attempts before they cause significant operational disruption.