CVE-2026-93064 in Linux
Summary
by MITRE • 09/17/2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: mvm: fix off-by-one in TXF key sanitiser
iwl_mvm_frob_txf_key_iter() tracks the last matched byte position in loop variable 'i'. When a full key match is found (match == keylen), 'i' points at the last byte of the matched key. The memset start offset should therefore be i + 1 - keylen, not i - keylen; the current code zeroes one byte before the match and leaves the final key byte un-sanitised.
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified in the Linux kernel within the Intel wireless driver subsystem represents a critical memory safety flaw rooted in an off-by-one error during cryptographic material sanitization. Specifically, this issue resides in the iwlwifi MVM (Multi-Station Virtual) module's TXF key sanitizer function, which is responsible for securely erasing sensitive encryption keys from system memory after they are no longer needed or when transitioning between security contexts. The core technical flaw lies within the iteration logic of the iwl_mvm_frob_txf_key_iter() routine, where a loop variable tracks the position of matched bytes in a buffer containing key material. When a complete match against the target key length is detected, the current implementation incorrectly calculates the starting offset for the memory zeroing operation by using an index that points to the last byte of the matched sequence rather than advancing past it. This miscalculation results in the memset function beginning one position too early relative to the intended boundary or failing to cover the final byte depending on the specific pointer arithmetic interpretation, but effectively leading to incomplete sanitization.
From a technical perspective, this is classified as CWE-193 Off-by-One Error, which frequently leads to buffer over-reads or insufficient memory clearing operations. In the context of cryptographic key management, the failure to fully overwrite sensitive data in RAM constitutes a significant security weakness often categorized under CWE-226 Sensitive Information Unintended Exposure. The operational impact of this vulnerability is severe because residual key material remains accessible in system memory even after it has been logically removed from active use by the driver. Attackers with local access privileges, or potentially remote attackers exploiting other vulnerabilities to achieve code execution, could perform forensic analysis on memory dumps or utilize kernel debugging interfaces to extract these lingering cryptographic keys. The presence of un-sanitized key bytes allows for potential decryption of past traffic if session keys are recovered, thereby undermining the confidentiality guarantees provided by WPA3 and other Wi-Fi security protocols implemented through this driver.
This vulnerability aligns with ATT&CK technique T1005 Data from Local System as it involves the extraction of sensitive information directly from memory resources without direct user interaction or network-based exploitation vectors for the initial access phase, though lateral movement might follow if keys are reused across different contexts. The mitigation strategy requires an immediate patch to correct the pointer arithmetic within the iwl_mvm_frob_txf_key_iter() function. Developers must ensure that when a full key match is identified, the loop variable or offset calculation accounts for the entire length of the matched data by adjusting the start index appropriately before invoking memory zeroing routines. System administrators should apply kernel updates provided by their distribution vendors as soon as they become available to close this gap in secure coding practices. Furthermore, implementing strict static analysis tools configured to detect off-by-one errors and enforcing rigorous code review processes for cryptographic operations can prevent similar defects from entering the production environment in future development cycles.