CVE-2026-64440

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

staging: rtl8723bs: fix OOB write in HT_caps_handler()

HT_caps_handler() iterates pIE->length bytes and writes into

HT_caps.u.HT_cap[], which is a fixed 26-byte array (sizeof struct

HT_caps_element). Because pIE->length is a raw u8 from an over-the-air

802.11 AssocResponse frame and is never validated, a malicious AP can

set it up to 255, causing up to 229 bytes of out-of-bounds writes into

adjacent fields of struct mlme_ext_info.

Truncate the iteration count to the size of HT_caps.u.HT_cap using

umin() so that data from a longer-than-expected IE is silently ignored

rather than written out of bounds, preserving interoperability with APs

that pad the element. An early return on oversized IEs was considered

but rejected: it would bypass the pmlmeinfo->HT_caps_enable = 1

assignment that precedes the loop, silently disabling HT mode for APs

that append extra bytes to the HT Capabilities IE.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References