CVE-2026-93063 in Linux
Summary
by MITRE • 09/17/2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: mei: check SAP message length before reading it
Verify the SAP message size is not larger than the local buffer before reading the message to avoid buffer overflow.
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Analysis
by VulDB Data Team • 09/18/2026
The identified vulnerability resides within the Intel wireless driver subsystem, specifically in the interaction between the iwlwifi component and the Management Engine Interface (MEI) layer of the Linux kernel. This issue stems from a critical absence of input validation regarding the length field associated with Service Access Point SAP messages received by the MEI interface. In systems utilizing this hardware architecture, the wireless driver communicates with the Intel Management Engine via specific message protocols that include variable-length data payloads. The core technical flaw is a missing bounds check before memory operations are performed on these incoming messages. When an SAP message arrives, the kernel code proceeds to read and process its contents without first verifying whether the declared size of the payload exceeds the capacity of the local buffer allocated for storage. This oversight creates a classic buffer overflow condition where data written into the fixed-size stack or heap buffer spills over into adjacent memory regions.
From a technical perspective, this vulnerability is categorized under CWE-120 Buffer Copy without Checking Size of Input Classic and potentially CWE-787 Out-of-bounds Write depending on the specific allocation context within the kernel space. The lack of validation allows an attacker who can influence or inject messages into the MEI communication channel to craft a malicious SAP message with an artificially inflated length field. Upon processing, this malformed input causes the driver to write data beyond the boundaries of the allocated buffer. In the Linux kernel environment, such memory corruption is particularly severe because it compromises the integrity of critical system structures that reside in adjacent memory locations. This can lead to immediate kernel panics due to segmentation faults or more insidious scenarios where an attacker achieves arbitrary code execution by overwriting function pointers or control flow data within the kernel address space.
The operational impact of this vulnerability is significant, as it affects systems relying on Intel wireless adapters with active Management Engine integration. An unauthenticated local user or a remote adversary capable of interacting with the MEI interface could exploit this flaw to escalate privileges from an unprivileged state to root level access. This effectively grants full control over the underlying operating system, allowing for data exfiltration, persistence mechanisms installation, and lateral movement within the network infrastructure. Furthermore, even if exploitation for code execution is mitigated by kernel hardening features like KASLR or SMEP, the vulnerability remains a viable vector for Denial of Service attacks through systematic memory corruption that destabilizes the kernel state.
Mitigation strategies primarily involve applying the upstream Linux kernel patch that introduces explicit length validation prior to buffer reads. System administrators should ensure their systems are updated with the latest stable kernel versions containing this fix. For environments where immediate patching is not feasible, network segmentation policies restricting access to MEI interfaces and strict monitoring of driver logs for anomalous memory allocation patterns can provide limited defensive coverage. Additionally, enabling Kernel Self-Protection features such as stack protector randomization and full page heap protection can increase the difficulty of successful exploitation by making it harder to predict memory layouts or corrupt critical control structures without triggering immediate detection mechanisms.