CVE-2026-98340

Received Received - Intake

BaseFortify

Publication date: 2026-10-06

Last updated on: 2026-10-19

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: only group hidden BSSes with beacon entries When a probe response for an unknown BSS comes in, __cfg80211_bss_update() looks for an existing entry with the same BSSID and a hidden (zero-length or NUL-filled) SSID, and if it finds one it groups them, using the beacon IEs from the existing entry. But that could find another entry without a beacon, if it was also from a probe response (with SSID), so there's a group without beacon elements. If a beacon with a hidden SSID for that BSSID arrives later, cfg80211_combine_bsses() goes looking for the probe response entries that belong to it - i.e. entries with the same BSSID and channel that have no beacon IEs - and finds those two. They are already grouped with each other, so it hits its WARN_ON_ONCE(bss->pub.hidden_beacon_bss) WARN_ON_ONCE(!list_empty(&bss->hidden_list)) which are there because an entry without beacon elements is not supposed to be part of a group yet. Only combine entries when a beacon was already received, ones that are kept separate will be combined when a beacon arrives.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-10-06

Last Modified

2026-10-19

Generated

2026-10-19

AI Q&A

2026-10-06

EPSS Evaluated

2026-10-18

NVD

CVE-2026-98340

EUVD

EUVD-2026-93325

Affected Vendors & Products

Vendor	Product	Version / Range
Linux	Linux	4593c4cbe1c96b3995727dc42f6aa103f4ff5afc
Linux	Linux	4593c4cbe1c96b3995727dc42f6aa103f4ff5afc
Linux	Linux	4593c4cbe1c96b3995727dc42f6aa103f4ff5afc
Linux	Linux	4593c4cbe1c96b3995727dc42f6aa103f4ff5afc
Linux	Linux	4593c4cbe1c96b3995727dc42f6aa103f4ff5afc
Linux	Linux	4593c4cbe1c96b3995727dc42f6aa103f4ff5afc
Linux	Linux	4593c4cbe1c96b3995727dc42f6aa103f4ff5afc
Linux	Linux	4593c4cbe1c96b3995727dc42f6aa103f4ff5afc
Linux	Linux	3.9

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves improper handling of hidden BSS (Basic Service Set) entries in Wi-Fi networks. When a probe response for an unknown network arrives, the system incorrectly groups it with existing hidden SSID entries even if the new entry lacks beacon information. Later, when a beacon with a hidden SSID arrives, the system attempts to combine entries but triggers a warning due to inconsistent grouping logic.

Detection Guidance

This vulnerability is specific to the Linux kernel's wifi configuration and may not have direct detection commands. Monitor kernel logs for warnings related to BSS grouping or hidden SSID handling. Check for unusual wireless network behavior or crashes in the cfg80211 module.

Impact Analysis

This vulnerability could lead to Wi-Fi network instability or unexpected behavior in Linux systems managing wireless connections. It may cause crashes or incorrect network associations due to improper handling of hidden SSID networks, potentially disrupting wireless connectivity.

Compliance Impact

This vulnerability is specific to the Linux kernel's wifi configuration and does not directly impact compliance with standards like GDPR or HIPAA. It involves a technical issue in handling hidden BSS (Basic Service Set) entries in wireless networks, which could lead to incorrect grouping of network entries but does not involve data exposure or privacy violations.

Mitigation Strategies

Update your Linux kernel to the latest stable version to ensure the vulnerability is patched. If immediate patching is not possible, disable wireless interfaces temporarily or restrict network access until the update is applied.

Hi! I’m here to help you understand CVE-2026-98340. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70