CVE-2026-53000
HIGHIn 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…
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-53000 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-53000 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-53000. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-53000 in your dependencies?
O3 detects CVE-2026-53000 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.