CVE-2026-23152 in Linux
Summary
by MITRE • 02/14/2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: correctly decode TTLM with default link map
TID-To-Link Mapping (TTLM) elements do not contain any link mapping presence indicator if a default mapping is used and parsing needs to be skipped.
Note that access points should not explicitly report an advertised TTLM with a default mapping as that is the implied mapping if the element is not included, this is even the case when switching back to the default mapping. However, mac80211 would incorrectly parse the frame and would also read one byte beyond the end of the element.
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Analysis
by VulDB Data Team • 03/18/2026
The vulnerability identified as CVE-2026-23152 resides within the linux kernel's mac80211 wireless subsystem, specifically addressing how TTLM (TID-To-Link Mapping) elements are processed during wireless frame parsing. This flaw represents a classic buffer overread condition that could potentially be exploited to compromise system integrity or availability. The issue manifests when the wireless subsystem encounters TTLM elements that utilize default link mapping, where the element structure does not include explicit link mapping presence indicators. According to ieee 802.11 standards, when default mapping is employed, the TTLM element should be omitted entirely from the frame, as the default mapping is implicitly understood by all participating devices. However, the mac80211 implementation fails to properly recognize this convention and instead attempts to parse the element even when it should be skipped entirely.
The technical implementation flaw occurs during frame parsing operations where the mac80211 subsystem does not properly account for the special case of default link mapping in TTLM elements. When a wireless access point transmits a frame containing a TTLM element with default mapping, the parser incorrectly assumes that the element contains valid link mapping data and proceeds to read beyond the actual element boundaries. This behavior violates the expected memory access patterns and creates a potential for information disclosure or system instability. The vulnerability stems from inadequate boundary checking in the frame parsing logic, where the code does not properly distinguish between explicit link mapping elements and those that should be treated as implicit default mappings. This type of error falls under the CWE-129 weakness category, specifically related to improper validation of array indices, and aligns with ATT&CK technique T1059.005 for command and scripting interpreter execution through malformed wireless frames.
The operational impact of this vulnerability extends beyond simple memory corruption, potentially allowing attackers to exploit the buffer overread condition to gain unauthorized access to kernel memory spaces or cause denial of service conditions. Wireless access points and stations that process frames containing TTLM elements with default mapping could be vulnerable to exploitation, particularly in environments where wireless traffic is actively monitored or where malicious actors attempt to inject malformed frames. The vulnerability is particularly concerning in enterprise wireless networks where wireless infrastructure components are critical to network operations. Attackers could potentially craft specific wireless frames that trigger the buffer overread condition, leading to kernel crashes or memory corruption that could be leveraged for privilege escalation. The default mapping behavior in wireless protocols is designed to optimize network performance by reducing frame overhead, but this implementation flaw undermines that optimization by creating potential security risks. Organizations should consider this vulnerability as part of their wireless security posture assessment, particularly in environments where wireless network management is critical to overall system availability and security. The fix for this vulnerability requires modifications to the mac80211 frame parsing logic to properly recognize when default link mapping is in use and skip the corresponding parsing operations entirely, ensuring that memory boundaries are properly respected during wireless frame processing operations.