CVE Catalog

CVE-2026-53000

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.13%

3th percentile - higher than 3% of all known CVEs

Summary

In the Linux kernel's netfilter/nat subsystem, a vulnerability was found where NAT hook registration structures (ops) were not freed using kfree_rcu. This can cause use-after-free when userspace dumps active hooks via nfnetlink_hook (introduced in v5.14).

Risk Assessment

The organization risks privilege escalation or system crash (kernel panic) due to memory corruption or access to freed structures when monitoring NAT rules via network management tools.

Recommendation

Immediately update the Linux kernel to a version containing the fix (commit using kfree_rcu in nf_nat_register_fn). A system reboot is required after the update.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS