CVE-2026-64440 PUBLISHED

staging: rtl8723bs: fix OOB write in HT_caps_handler()

Assigner: Linux
Reserved: 19.07.2026 Published: 25.07.2026 Updated: 25.07.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 554c0a3abf216c991c5ebddcdb2c08689ecd290b to 37f642d47c3648a707df3ceb092eee1adffbfd28 (excl.)
  • affected from 554c0a3abf216c991c5ebddcdb2c08689ecd290b to 8c872b47c7fc32e95e0da1db7512388794adcd69 (excl.)
  • affected from 554c0a3abf216c991c5ebddcdb2c08689ecd290b to bb3b942da4123b55d1cacf19d1a7d5ba15dbf83a (excl.)
  • affected from 554c0a3abf216c991c5ebddcdb2c08689ecd290b to 918537a0fbed85aab61fa28ad75e6279070610c9 (excl.)
  • affected from 554c0a3abf216c991c5ebddcdb2c08689ecd290b to 6f91621fc45025ad3c0be796b70e6e4cee22fc69 (excl.)
  • affected from 554c0a3abf216c991c5ebddcdb2c08689ecd290b to 225b6d3fc7e99ac3d20b6c861d1e47d24e7ea31d (excl.)
  • affected from 554c0a3abf216c991c5ebddcdb2c08689ecd290b to f8001e1a516ba3b495728c65b61f799cbfad6bd0 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 4.12 is affected
  • unaffected from 0 to 4.12 (excl.)
  • unaffected from 5.15.212 to 5.15.* (incl.)
  • unaffected from 6.1.178 to 6.1.* (incl.)
  • unaffected from 6.6.145 to 6.6.* (incl.)
  • unaffected from 6.12.96 to 6.12.* (incl.)
  • unaffected from 6.18.39 to 6.18.* (incl.)
  • unaffected from 7.1.4 to 7.1.* (incl.)
  • unaffected from 7.2-rc3 to * (incl.)

References