CVE Catalog

CVE-2026-23351

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.12%

2th percentile - higher than 2% of all known CVEs

Summary

A Use-After-Free vulnerability was found in the Linux kernel's netfilter pipapo set type. The issue arises from prolonged garbage collection (GC) in a non-preemptible context under a large number of expired elements, causing soft lockups and RCU stalls. The fix splits GC into unlink and reclaim phases to prevent access to freed memory.

Risk Assessment

The organization faces a local denial of service (DoS) and potential data integrity compromise due to access to freed memory, which could lead to privilege escalation or information disclosure.

Recommendation

Apply the patch that splits garbage collection into unlink and reclaim phases immediately, available in the latest stable Linux kernel. Update to a kernel version containing commit 35f83a75529a and related fixes.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_set_pipapo: split gc into unlink and reclaim phase Yiming Qian reports Use-after-free in the pipapo set type: Under a large number of expired elements, commit-time GC can run for a very long time in a non-preemptible context, triggering soft lockup warnings and RCU stall reports (local denial of service). We must split GC in an unlink and a reclaim phase. We cannot queue elements for freeing until pointers have been swapped. Expired elements are still exposed to both the packet path and userspace dumpers via the live copy of the data structure. call_rcu() does not protect us: dump operations or element lookups starting after call_rcu has fired can still observe the free'd element, unless the commit phase has made enough progress to swap the clone and live pointers before any new reader has picked up the old version. This a similar approach as done recently for the rbtree backend in commit 35f83a75529a ("netfilter: nft_set_rbtree: don't gc elements on insert").

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