CVE-2023-53304 netfilter: nft_set_rbtree: fix overlap expiration walk

What is CVE-2023-53304?

CVE-2023-53304 is a medium-severity vulnerability in Linux kernel, published on 16 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nft_set_rbtree: fix overlap expiration walk

The lazy gc on insert that should remove timed-out entries fails to release the other half of the interval, if any.

Can be reproduced with tests/shell/testcases/sets/0044interval_overlap_0 in nftables.git and kmemleak enabled kernel.

Second bug is the use of rbe_prev vs. prev pointer. If rbe_prev() returns NULL after at least one iteration, rbe_prev points to element that is not an end interval, hence it should not be removed.

Lastly, check the genmask of the end interval if this is active in the current generation.

Weakness: CWE-476

Which versions are affected by CVE-2023-53304?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2023-53304?

Apply the vendor's patch.

Is CVE-2023-53304 being exploited?

There is no known exploitation of CVE-2023-53304 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2023-53304, DEBIAN-CVE-2023-53304, GHSA-phm5-wwmp-pqvr, UBUNTU-CVE-2023-53304.