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.
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.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 06 Oct 2026 09:00:00 +0000
| Type | Values Removed | Values 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. | |
| Title | wifi: cfg80211: only group hidden BSSes with beacon entries | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-06T08:46:30.796Z
Reserved: 2026-09-25T10:25:14.342Z
Link: CVE-2026-98340
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-06T09:18:26.720
Modified: 2026-10-06T09:18:26.720
Link: CVE-2026-98340
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.