CVE-2026-64440

staging: rtl8723bs: fix OOB write in HT_caps_handler()

HIGH
8.1
CVSS Score
Published: July 25, 2026 at 08:51 AM UTC
Updated: October 19, 2026 at 09:17 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH8.1
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.12 ≤ v < 5.15.2125.16 ≤ v < 6.1.1786.13 ≤ v < 6.18.396.19 ≤ v < 7.1.46.2 ≤ v < 6.6.1456.7 ≤ v < 6.12.96554c0a3abf216c991c5ebddcdb2c08689ecd290b7.27.2 rc17.2 rc2
Vendor states this is fixed in 225b6d3fc7e99ac3d20b6c861d1e47d24e7ea31d (fixed)
Vendor states this is fixed in 37f642d47c3648a707df3ceb092eee1adffbfd28 (fixed)
Vendor states this is fixed in 6f91621fc45025ad3c0be796b70e6e4cee22fc69 (fixed)
Vendor states this is fixed in 8c872b47c7fc32e95e0da1db7512388794adcd69 (fixed)
Vendor states this is fixed in 918537a0fbed85aab61fa28ad75e6279070610c9 (fixed)
Vendor states this is fixed in bb3b942da4123b55d1cacf19d1a7d5ba15dbf83a (fixed)
Vendor states this is fixed in f8001e1a516ba3b495728c65b61f799cbfad6bd0 (fixed)
Vendor states this is fixed in 4.12 (unaffected)
Vendor states this is fixed in 5.15.212 (unaffected)
Vendor states this is fixed in 6.1.178 (unaffected)
Vendor states this is fixed in 6.12.96 (unaffected)
Vendor states this is fixed in 6.18.39 (unaffected)
Vendor states this is fixed in 6.6.145 (unaffected)
Vendor states this is fixed in 7.1.4 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.1HIGHLinux
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-787

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