CVE-2026-98422: Linux kernel · wifi: mac80211: reset the AP_VLAN tailroom counter on ifdown
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 28 Oct 2026, 01:28 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Exploitation evidence
Disclosed: evidence found.
CVE published 14 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2026-98422 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98422 (opens in a new tab)
- git.kernel.org/stable/c/4b54d01b48445b66c9e576de92b90a3a3ae7b34a (opens in a new tab)
- git.kernel.org/stable/c/b0b32d3f163d24ea7134380666193bf398e9dc0b (opens in a new tab)
- git.kernel.org/stable/c/875835377d8d62c849b4eb03a7abfafa71d7668f (opens in a new tab)
- git.kernel.org/stable/c/3d76b45e8432c0d75fcb9e90d92eaa3176898adf (opens in a new tab)
- git.kernel.org/stable/c/7775759e3cb35ef5a571b2d877c2a9b70a5d5f08 (opens in a new tab)
- git.kernel.org/stable/c/4504f3960dc4501c73be9f99eabda2e26e9db41e (opens in a new tab)
- git.kernel.org/stable/c/304a874670a0b6ab5589a7f60b4af0251797b121 (opens in a new tab)
- git.kernel.org/stable/c/f6b34a7d64324faf28eedc0f8678b0f832f1cc36 (opens in a new tab)