CVE-2026-98340
wifi: cfg80211: only group hidden BSSes with beacon entries
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.
INFO
Published Date :
Oct. 6, 2026, 9:18 a.m.
Last Modified :
Oct. 6, 2026, 9:18 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Apply the latest Linux kernel update.
- Ensure all BSS entries have beacon information.
- Verify correct grouping of BSS entries.
- Restart affected network services.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-98340.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-98340 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-98340
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-98340 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-98340 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Oct. 06, 2026
Action Type Old Value New Value Added 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98340.json">CVE-2026-98340</a> Added Reference https://git.kernel.org/stable/c/068843ed0902c552a13860c5ec6b2ca65b57a065 Added Reference https://git.kernel.org/stable/c/332ea1502c46f53375cb109fa82bfaff818f3a41 Added Reference https://git.kernel.org/stable/c/3658093df69849daf4f813a8f087f358e13be203 Added Reference https://git.kernel.org/stable/c/4cd6a518ce7527284bbc9baab5fa2453a7d477c2 Added Reference https://git.kernel.org/stable/c/73365b81630b57e1a1f9d50dc87281797855c2ac Added Reference https://git.kernel.org/stable/c/7405dd19bda4537a2843637d8d7bed1efd4776cf Added Reference https://git.kernel.org/stable/c/74ed0d992f392c75e1969415527e06df3f7a4034 Added Reference https://git.kernel.org/stable/c/86235be788094131912e9bd8412b358d91d99f49