CVE-2026-72442: Linux kernel · netfilter: flowtable: fix and simplify IP6IP6 tunnel handling
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 7.0.0-1013.13~24.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-1013.13~24.04.1, 7.0.0-1017.17~24.04.1, 7.0.0-1016.16~24.04.1 +12
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 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
Upgrade to a fixed release listed under Affected software.
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.
AI-suggested
A patch is available and should be applied immediately. The vendor advisory from Ubuntu confirms that the issue is fixed in updated Linux kernel packages. After applying the update, a system reboot is required. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be necessary. Follow the vendor's update instructions carefully to ensure full remediation.
Description
A high-severity vulnerability in the Linux kernel's netfilter flowtable subsystem related to IP6IP6 tunnel handling has been resolved. The issue involved improper handling of the outer IPv6 header in packet processing, which could allow an attacker to compromise the system. The fix includes changes to how the kernel processes IPv6 tunnels, simplifying the code and removing unsupported options. Multiple Linux kernel versions are affected, and patches are available. Users should update and reboot to apply the fixes.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72442 (opens in a new tab)
- git.kernel.org/stable/c/7f8d816a9aa2729d270418f00c9ef5e85bfc1b31 (opens in a new tab)
- git.kernel.org/stable/c/f4c2d8668d85ed125985da663c824a9c25498257 (opens in a new tab)
- ubuntu.com/security/CVE-2026-72442 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72442 (opens in a new tab)
- git.kernel.org/linus/f4c2d8668d85ed125985da663c824a9c25498257 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)