CVE-2026-68308 in Linux
Summary
by MITRE • 08/10/2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7996: check pointer returned by mt76_connac_get_he_phy_cap()
mt76_connac_get_he_phy_cap routine can theoretically return NULL so check cap pointer before dereferencing it.
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Analysis
by VulDB Data Team • 08/10/2026
The vulnerability in question affects the mt7996 wireless driver within the Linux kernel's mt76 subsystem, specifically concerning the handling of HE (High Efficiency) PHY capabilities during wireless connection establishment. This issue represents a classic null pointer dereference vulnerability that could potentially lead to system instability or privilege escalation. The flaw exists in the wireless networking stack where the mt76_connac_get_he_phy_cap function is designed to retrieve HE PHY capability information but can theoretically return a NULL pointer under certain conditions. When this function returns NULL, subsequent code attempts to dereference the returned pointer without proper validation, creating an exploitable condition that could crash the kernel or allow malicious actors to execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability stems from inadequate input validation within the wireless driver's capability parsing logic. The mt76_connac_get_he_phy_cap routine, which is responsible for extracting High Efficiency PHY capabilities from wireless connection parameters, may return NULL when it cannot properly parse or retrieve the required HE PHY information. This can occur during edge cases such as malformed wireless frames, incomplete connection handshakes, or specific hardware configurations where the expected capability data is either missing or corrupted. The lack of proper NULL pointer checks before dereferencing the returned capability structure creates a direct path for kernel crashes or potential exploitation scenarios where an attacker could manipulate wireless frame parameters to trigger this condition.
From an operational impact perspective, this vulnerability affects systems running Linux kernels with mt7996 wireless drivers, particularly those supporting Wi-Fi 6 (802.11ax) functionality. The vulnerability can lead to system instability through kernel panics or crashes when legitimate wireless connections attempt to negotiate HE PHY capabilities. In environments where wireless connectivity is critical for operations, such as enterprise networks, IoT deployments, or embedded systems, this could result in service disruption and potential denial of wireless access. The attack surface extends beyond simple DoS conditions as the null pointer dereference represents a potential privilege escalation vector that could allow attackers to execute code at kernel level with full system privileges, particularly if combined with other exploitation techniques.
The vulnerability aligns with CWE-476 which specifically addresses NULL Pointer Dereference, and maps to several ATT&CK techniques including T1059 for command and control through kernel-level persistence and T1068 for privilege escalation. Mitigation strategies should focus on implementing proper pointer validation checks before any dereference operations within the wireless driver code. The recommended approach involves adding explicit NULL checks after calling mt76_connac_get_he_phy_cap and ensuring that all subsequent operations only proceed when valid capability data is available. Additionally, system administrators should ensure timely kernel updates are applied to address this vulnerability, particularly in environments where wireless network security is paramount. The fix typically involves modifying the driver code to include proper error handling and graceful degradation when HE PHY capabilities cannot be retrieved, preventing the kernel from crashing while maintaining functional wireless connectivity through alternative PHY modes or fallback mechanisms.