CVE-2026-64440
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.
Affected versions
Linux kernel versions
4.12
and later are affected. Fixed in
5.15.212,
6.1.178,
6.6.145,
6.12.96,
6.18.39,
7.1.4,
7.2-rc3
and their respective stable series.
References
7 totalFrequently asked questions
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What is CVE-2026-64440?
CVE-2026-64440 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 4.12 onward and has been patched in 5.15.212, 6.1.178, 6.6.145 and others. CVE-2026-64440 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-64440?
Yes. CVE-2026-64440 has been patched. Fixed versions include 5.15.212, 6.1.178, 6.6.145 and others. If you are running Linux kernel 4.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-64440 actively exploited?
No. CVE-2026-64440 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.