CVE-2026-90018 is a vulnerability in Linux Kernel
Published on September 16, 2026
staging: rtl8723bs: fix OOB read / stack overflow in rtw_get_wps_attr()
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix OOB read / stack overflow in rtw_get_wps_attr()
rtw_get_wps_attr() walks WPS attributes inside a WPS IE taken from
a wireless management frame. For each candidate attribute it only
checks that the fixed 4-byte attribute header (2-byte ID + 2-byte
length) fits inside the IE:
if (attr_ptr + 4 > wps_ie + wps_ielen)
break;
u16 attr_id = get_unaligned_be16(attr_ptr);
u16 attr_data_len = get_unaligned_be16(attr_ptr + 2);
u16 attr_len = attr_data_len + 4;
attr_data_len (and therefore attr_len) is read directly from the
wire and is never checked against the remaining bytes in the IE
before being used as the size of:
memcpy(buf_attr, attr_ptr, attr_len);
Since attr_len is fully attacker controlled (0 to 65535+4), this is
both a heap OOB read of wps_ie, and, more seriously, a stack buffer
overflow at several call sites where buf_attr is a single-byte
stack variable, e.g. rtw_get_wps_attr_content()'s callers passing
WPS_ATTR_SELECTED_REGISTRAR into a stack "u8 sr"/"u8
selected_registrar" (drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c,
drivers/staging/rtl8723bs/core/rtw_mlme_ext.c). A crafted WPS IE in a
beacon or probe response processed during scanning can therefore
smash the stack of the parsing thread.
rtw_get_wps_attr_content() itself has no independent length check
and simply trusts the attr_len it gets back from rtw_get_wps_attr(),
so fixing the bound here also fixes that caller.
The "attr_ptr + 4 > wps_ie + wps_ielen" header check above was added
by commit 1463ca3ec6601 ("staging: rtl8723bs: fix OOB reads in
rtw_get_sec_ie(), rtw_get_wapi_ie(), and rtw_get_wps_attr()"), which
bounded the fixed header but never extended the check to cover the
variable-length attribute data that follows it. Add that missing
check before attr_len is used as a memcpy() length or accepted as a
match.
Products Associated with CVE-2026-90018
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Affected Versions
Linux:- Version 554c0a3abf216c991c5ebddcdb2c08689ecd290b and below 931640dfcb8cfa08f6cfb46229716d8072356420 is affected.
- Version 554c0a3abf216c991c5ebddcdb2c08689ecd290b and below 3a6457ebf39080b87c712657fdb38f34a24fc3ff is affected.
- Version 554c0a3abf216c991c5ebddcdb2c08689ecd290b and below fd5e24ea8373347d0352f153a66e8647337d1b10 is affected.
- Version 554c0a3abf216c991c5ebddcdb2c08689ecd290b and below a53d1ac9ce63db07943b2b2248111003851fb00f is affected.
- Version 554c0a3abf216c991c5ebddcdb2c08689ecd290b and below ff61aa3289355dafa811550a1764691cd1f5d33b is affected.
- Version 554c0a3abf216c991c5ebddcdb2c08689ecd290b and below 34f51d196c43a42046d229de5e79025d5ca553ca is affected.
- Version 554c0a3abf216c991c5ebddcdb2c08689ecd290b and below 99aa998dec83ba180822f70e6d48a514fc81c20d is affected.
- Version 4.12 is affected.
- Before 4.12 is unaffected.
- Version 5.15.221, <= 5.15.* is unaffected.
- Version 6.1.188, <= 6.1.* is unaffected.
- Version 6.6.157, <= 6.6.* is unaffected.
- Version 6.12.110, <= 6.12.* is unaffected.
- Version 6.18.51, <= 6.18.* is unaffected.
- Version 7.2.5, <= 7.2.* is unaffected.
- Version 7.3-rc2, <= * is unaffected.