Improper Check for Unusual or Exceptional Conditions in Linux kernel - CVE-2026-98340

Vulnerability details

The vulnerability allows a remote attacker to trigger kernel warnings and prevent beacon data from being populated or updated for grouped BSS entries.

The vulnerability exists due to improper validation of beacon data presence in cfg80211 BSS grouping when processing probe responses and subsequent hidden-SSID beacons. A remote attacker can transmit probe responses that cause entries without beacon data to be grouped, followed by a hidden-SSID beacon with the same BSSID and channel, to trigger kernel warnings and prevent beacon data from being populated or updated for grouped BSS entries.

A hidden SSID can be zero-length or NUL-filled.

Affected software

How to mitigate CVE-2026-98340

External References

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

Related Security Bulletins

• Improper Check for Unusual or Exceptional Conditions in Linux kernel wireless
• Debian update for linux