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VulnerabilityPublished Updated

CVE-2026-23272: Linux kernel · netfilter: nf_tables: unconditionally bump set->nelems before insertion

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in e3ccb11fc8249759d23326038c8db987ddaabc77 : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in e3ccb11fc8249759d23326038c8db987ddaabc77, def602e498a4f951da95c95b1b8ce8ae68aa733a, ccb8c8f3c1127cf34d18c737309897c68046bf21 +4
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 20 Mar 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • >=4.9.33 <4.10
Fixed in
  • e3ccb11fc8249759d23326038c8db987ddaabc77
  • def602e498a4f951da95c95b1b8ce8ae68aa733a
  • ccb8c8f3c1127cf34d18c737309897c68046bf21
  • 6826131c7674329335ca25df2550163eb8a1fd0c
  • 86bc4b1a0f672d47ac19f9022432cb6a2e01cb33
  • 25fcaef7948912652905e96922f36583a84fffed
  • 4.10
LinuxLinuxAffected
  • =4.10
Fixed in–

AI-suggested

A fix for this vulnerability is available and included in Linux kernel version 4.10 and related commits. Users and administrators should upgrade affected Linux kernel versions (>=4.9.33 <4.10 and =4.10) to the fixed versions to mitigate this issue. No additional mitigation steps are indicated beyond applying the official patch.

Description

CVE-2026-23272 is a high-severity use-after-free vulnerability in the Linux kernel's netfilter nf_tables subsystem. It occurs when the set of elements is full, and a new element is added and then removed without waiting for the RCU grace period, potentially allowing RCU readers to access freed memory. The issue is fixed by properly handling the set_full flag and safely unwinding the set to its previous state or by synchronizing RCU in the error path. Affected Linux kernel versions include 4.9.33 through 4.10.

References

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