CVE-2026-72248: Linux kernel · netfilter: flowtable: support IPIP tunnel with direct xmit
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, 12:55 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 promptly. The vendor advisory from Ubuntu confirms that fixes have been released in updated Linux kernel packages. Users should update their systems to the fixed kernel versions and reboot to apply changes. Due to ABI changes, recompilation and reinstallation of third-party kernel modules may be required. No alternative mitigations are indicated as the issue is resolved by the official fix.
Description
A vulnerability in the Linux kernel's netfilter flowtable subsystem involving IPIP tunnels with direct transmit (xmit) has been resolved. The issue arises because no destination entry (dst_entry) is provided to check the socket buffer (skb) headroom and set the IP header fragment offset, leading to invalid destination usage and potential kernel crash during tunnel transmission. The fix involves restructuring how route state is preserved and released for direct transmit tunnel flows. This vulnerability affects multiple Linux kernel versions and has been addressed in updated kernel packages.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72248 (opens in a new tab)
- git.kernel.org/stable/c/0880c4ed122d0cddc9f29a2b28f055d1f24f0fca (opens in a new tab)
- git.kernel.org/stable/c/fa7395c02d95e51bad2952325d2d6503bfbad437 (opens in a new tab)
- ubuntu.com/security/CVE-2026-72248 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72248 (opens in a new tab)
- git.kernel.org/linus/fa7395c02d95e51bad2952325d2d6503bfbad437 (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)