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CVE-2026-98422

Linux: wifi: mac80211: reset the AP_VLAN tailroom counter on ifdown

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
NoneNot scored
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.22%Chance of exploitation activity in the next 30 days, higher than 11% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in304a874670a0b6ab5589a7f60b4af0251797b121Also 7775759e3cb35ef5a571b2d877c2a9b70a5d5f08, 3d76b45e8432c0d75fcb9e90d92eaa3176898adf and 3 moreCVE List
Published14 Oct 2026Updated 19 Oct 2026CVE List

What fixes it

  • 304a874670a0b6ab5589a7f60b4af0251797b121LinuxCVE List
  • 7775759e3cb35ef5a571b2d877c2a9b70a5d5f08LinuxCVE List
  • 3d76b45e8432c0d75fcb9e90d92eaa3176898adfLinuxCVE List
  • 4b54d01b48445b66c9e576de92b90a3a3ae7b34aLinuxCVE List
  • 875835377d8d62c849b4eb03a7abfafa71d7668fLinuxCVE List
  • 4504f3960dc4501c73be9f99eabda2e26e9db41eLinuxCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

In the Linux kernel, the following vulnerability has been resolved:

wifi: mac80211: reset the AP_VLAN tailroom counter on ifdown

On ifup, AP_VLAN interfaces get crypto_tx_tailroom_needed_cnt from the AP interface, but it's never decremented again unless the AP is also brought down. Thus, bringing the same AP_VLAN up again will increment the counter again and eventually hit the sanity check:

WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt != master->crypto_tx_tailroom_needed_cnt);

Reset it on ifdown to avoid that.

Text from CVE List

Affected versions 18

  • Linuxaffected: f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 before b0b32d3f163d24ea7134380666193bf398e9dc0bCVE List
  • Linuxaffected: f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 before f6b34a7d64324faf28eedc0f8678b0f832f1cc36CVE List
  • Linuxaffected: f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 before 304a874670a0b6ab5589a7f60b4af0251797b121CVE List
  • Linuxaffected: f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 before 7775759e3cb35ef5a571b2d877c2a9b70a5d5f08CVE List
  • Linuxaffected: f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 before 3d76b45e8432c0d75fcb9e90d92eaa3176898adfCVE List
  • Linuxaffected: f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 before 4b54d01b48445b66c9e576de92b90a3a3ae7b34aCVE List
  • Linuxaffected: f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 before 875835377d8d62c849b4eb03a7abfafa71d7668fCVE List
  • Linuxaffected: f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 before 4504f3960dc4501c73be9f99eabda2e26e9db41eCVE List
  • Linuxaffected: 4.1CVE List
  • Linuxunaffected: all versions before 4.1CVE List
  • Linuxunaffected: 5.10.271 through 5.10.*CVE List
  • Linuxunaffected: 5.15.222 through 5.15.*CVE List
  • Linuxunaffected: 6.1.189 through 6.1.*CVE List
  • Linuxunaffected: 6.6.158 through 6.6.*CVE List
  • Linuxunaffected: 6.12.112 through 6.12.*CVE List
  • Linuxunaffected: 6.18.54 through 6.18.*CVE List
  • Linuxunaffected: 7.2.8 through 7.2.*CVE List
  • Linuxunaffected: 7.3CVE List

References 8