CVE-2026-68309 in Linux
Summary
by MITRE • 08/10/2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: connac: fix possible NULL-pointer deref in mt76_connac_mcu_uni_bss_he_tlv()
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 resides within the mt76 wireless driver implementation for MediaTek MT7915 chipsets, specifically in the connection management unit handling of HE (High Efficiency) PHY capabilities. This issue manifests as a potential null pointer dereference during the processing of wireless network configuration parameters, particularly when dealing with BSS (Basic Service Set) HE capability TLVs. The flaw occurs in the mt76_connac_mcu_uni_bss_he_tlv function where the code attempts to access memory through a pointer that may not have been properly initialized or validated.
The technical root cause stems from the mt76_connac_get_he_phy_cap routine which serves as a helper function to retrieve HE PHY capability information from wireless network configurations. Under certain conditions, this routine can return a NULL pointer instead of valid capability data, creating a dangerous scenario where subsequent code attempts to dereference this uninitialized pointer without proper validation. This pattern violates fundamental defensive programming principles and creates an exploitable condition that could lead to kernel panic or arbitrary code execution in the most severe cases.
The operational impact of this vulnerability extends beyond simple system instability as it affects wireless connectivity and potentially provides attackers with opportunities to disrupt network services or escalate privileges within the kernel space. When the wireless driver encounters malformed or unexpected wireless configuration data, particularly during HE capability negotiation, the system may crash or become unresponsive. This represents a critical concern for enterprise deployments where wireless infrastructure reliability is paramount, as such an issue could be exploited to cause denial of service attacks against wireless networks.
Mitigation strategies should focus on implementing proper null pointer validation before any dereference operations within the affected code path. The fix requires adding explicit checks to verify that the capability pointer returned by mt76_connac_get_he_phy_cap is not NULL before proceeding with subsequent operations. This approach aligns with common security practices outlined in cwe-476 which addresses null pointer dereference vulnerabilities, and follows defensive programming principles recommended by various kernel security guidelines. Additionally, comprehensive input validation should be implemented to ensure that wireless configuration parameters meet expected formats and constraints.
From a threat modeling perspective, this vulnerability could be leveraged by attackers who can inject malformed wireless network configuration data or manipulate existing wireless communications to trigger the null pointer dereference condition. The attack surface is primarily limited to systems running affected kernel versions with MediaTek MT7915 wireless chipsets, but given the potential for privilege escalation and system instability, this represents a significant security concern. Network administrators should prioritize patching affected systems and implementing monitoring for unusual wireless network behavior that might indicate exploitation attempts. The fix demonstrates proper error handling practices that align with both industry standards and the specific requirements of kernel-level security implementations.