CVE-2026-98370: Linux kernel · xfrm: fix compat ALLOCSPI request use-after-free
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 6 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: xfrm: fix compat ALLOCSPI request use-after-free xfrm_state_netlink() builds the ALLOCSPI response with dump_one_state(), which already calls alloc_compat() with the response skb and header. xfrm_alloc_userspi() then calls alloc_compat() again, but passes the original request skb and its header. For a compat request, the translator therefore interprets the 228-byte compat xfrm_userspi_info as the 232-byte native layout and reads four bytes past the declared payload. It also publishes the translated child through the request's frag_list. A multicast clone of the request shares skb_shared_info and can observe that child. xfrm_user_rcv_msg() frees it after the request handler returns, racing a compat receiver which may still be copying from it and resulting in a use-after-free. Remove the redundant conversion. The response keeps its correct compat translation from dump_one_state(), and no child is attached to the inbound request.
References
- ubuntu.com/security/CVE-2026-98370 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98370 (opens in a new tab)
- git.kernel.org/linus/d1ebd9081879fd9ae9c8fb7e8928f19cc88ae320 (opens in a new tab)
- git.kernel.org/stable/c/17893987e52918c23945c42e47e894a936305a25 (opens in a new tab)
- git.kernel.org/stable/c/248433942155b42a0ef04a5806c8aca024ea7c33 (opens in a new tab)
- git.kernel.org/stable/c/2b63341e2ebc9b6f73cbd9214dbe7d46dd98c718 (opens in a new tab)
- git.kernel.org/stable/c/42971ea17c7a8afc0bdd5ca40648bf4e5bb7b810 (opens in a new tab)
- git.kernel.org/stable/c/494f2bee9d8d0ebcfa249ac41bed7fed26d119b4 (opens in a new tab)
- git.kernel.org/stable/c/bb63ab52a18273ec68340ac49aebbaa7b514ccd5 (opens in a new tab)
- git.kernel.org/stable/c/d1ebd9081879fd9ae9c8fb7e8928f19cc88ae320 (opens in a new tab)
- git.kernel.org/stable/c/e70f639aee2ff0def155c256cace9e0f81d998e2 (opens in a new tab)