NULL pointer dereference in Linux

CVE-2023-53304

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.

EPSS: 0.001 (4.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

  • Linux — versions 5.15.124, c9e6978e2725a7d4b6cd23b2facd3f11422c0643, 6.1.43
  • Linux Linux_kernel — versions 6.2, 6.5

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-53304?
CVE-2023-53304 is a medium-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2025-09-16.
How severe is CVE-2023-53304?
Medium severity. CVSS v3 base score is 5.5 out of 10.