CVE-2026-68472 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: validate EHT MLE before MLD ID read
cfg80211_gen_new_ie() copies ML probe response elements from the parent frame when the parent EHT multi-link element has an MLD ID matching the nontransmitted BSSID index.
The code only checked that the extension element had more than one byte before calling ieee80211_mle_get_mld_id(). That helper assumes a BASIC MLE with enough common info and documents that callers must first use ieee80211_mle_type_ok().
Attack chain: malicious AP sends a short EHT MLE in an MBSSID beacon. cfg80211_inform_bss_frame_data() stores the copied IE buffer. cfg80211_parse_mbssid_data() builds the nontransmitted BSS IE. cfg80211_gen_new_ie() sees the EHT MLE in the parent frame. ieee80211_mle_get_mld_id() then reads past the IE boundary.
Validate the MLE type and size before reading the MLD ID. This matches the contract required by the MLE helper and rejects the short element before any internal MLE fields are accessed.
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Analysis
by VulDB Data Team • 08/15/2026
The vulnerability described represents a critical buffer overflow condition within the linux kernel's wireless subsystem, specifically affecting the cfg80211 subsystem responsible for managing wireless configuration. This flaw exists in the handling of Enhanced High Throughput (EHT) multi-link elements within beacon frames, creating a potential avenue for privilege escalation or denial of service attacks. The issue manifests when processing malformed EHT Multi-Link Elements that contain insufficient data beyond the basic element header, leading to improper memory access patterns during wireless network configuration parsing.
The technical flaw stems from inadequate validation of Extended High Throughput (EHT) Multi-Link Element structures before accessing specific field values. The function cfg80211_gen_new_ie() performs a copy operation of ML probe response elements from parent frames when the EHT multi-link element contains an MLD ID matching the nontransmitted BSSID index. However, the implementation only validates that the extension element contains more than one byte before invoking ieee80211_mle_get_mld_id(), which assumes the presence of a complete BASIC MLE structure with sufficient common information fields. This violates the documented contract for the helper function that explicitly requires callers to first validate the MLE type using ieee80211_mle_type_ok() before attempting field access operations.
The operational impact of this vulnerability extends across wireless network security boundaries, as it can be exploited through malicious access point configurations that send malformed EHT Multi-Link Elements in MBSSID beacons. When processed by the kernel's wireless subsystem, these frames trigger a sequence where cfg80211_inform_bss_frame_data() stores the copied IE buffer, followed by cfg80211_parse_mbssid_data() constructing nontransmitted BSS information elements, and finally cfg80211_gen_new_ie() encountering the EHT MLE in the parent frame. The subsequent call to ieee80211_mle_get_mld_id() reads beyond the allocated IE boundary, potentially causing kernel memory corruption or arbitrary code execution. This vulnerability directly relates to CWE-129 and CWE-787 as it involves improper validation of input boundaries and buffer over-read conditions.
The attack chain demonstrates a sophisticated exploitation pattern that leverages wireless frame parsing logic within the kernel's cfg80211 subsystem. Malicious access points can craft specifically formatted EHT Multi-Link Elements with insufficient data length, causing the kernel to improperly handle memory references during beacon processing. This vulnerability aligns with ATT&CK technique T1059.007 for kernel-level code execution and represents a privilege escalation vector that could allow attackers to gain elevated privileges within the wireless subsystem. The patch implementation requires validating MLE type and size before reading the MLD ID, ensuring compliance with the helper function's documented contract and preventing access to incomplete or malformed element structures.
Mitigation strategies should focus on immediate kernel updates addressing this specific buffer overflow condition, alongside network monitoring to detect potential exploitation attempts through malformed beacon frames. System administrators should implement wireless intrusion detection systems capable of identifying suspicious EHT Multi-Link Element structures and consider network segmentation to limit the impact of successful exploitation attempts. The fix demonstrates proper defensive programming practices by enforcing preconditions before accessing structured data elements, aligning with industry standards for secure kernel development and preventing similar issues in related wireless subsystem components.