CVE-2026-90018

What it is

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.

At a glance

Exploitability

Can be exploited from the same network segment without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-09-11 19:38 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-09-16 11:17 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-10-19 09:18 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.4% in the next 30 days (EPSS).
• Severity: 8.8 HIGH (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2026-09-16 11:17 UTC

Last modified

2026-10-19 09:18 UTC

Exploit probability

0.4% · EPSS, next 30 days

Record status

Received

Attack profile CVSS 3.1 · 8.8

Attack vector

Adjacent network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-90018.md and follow it. Check whether this project is affected by CVE-2026-90018. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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