netfilter: nat: use kfree_rcu to release ops
CVE-2026-53000 · published 24 Jun 2026
How serious is it
- Severity: high, CVSS score 7.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-53000?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: e2cf17d3774c323ef6dab6e9f7c0cfc5e742afd9 to < ede973d62d26d9c550269af05366ab9e30fc92ee, e2cf17d3774c323ef6dab6e9f7c0cfc5e742afd9 to < 050f98e56782b14677c5bae50800e60775bbf6bb, e2cf17d3774c323ef6dab6e9f7c0cfc5e742afd9 to < 32fdd2e38e7435a368d88f5977a7d6585ebc8b0e, e2cf17d3774c323ef6dab6e9f7c0cfc5e742afd9 to < 3c7511f38ab511b791196b13ae48bf4973bf7dfd
- Linux Linux: 5.14
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
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.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/ede973d62d26d9c550269af05366ab9e30fc92ee
- git.kernel.org/stable/c/050f98e56782b14677c5bae50800e60775bbf6bb
- git.kernel.org/stable/c/32fdd2e38e7435a368d88f5977a7d6585ebc8b0e
- git.kernel.org/stable/c/3c7511f38ab511b791196b13ae48bf4973bf7dfd
- git.kernel.org/stable/c/6eda0d771f94267f73f57c94630aa47e90957915
Merged from CVE List. Last updated 25 Oct 2026. All vulnerabilities · RSS · JSON