CVE-2026-23399

Local denial of service via unreleased expression

Published Mar 28, 2026 · Updated Mar 28, 2026

Memory leak in the Linux Kernel nf_tables nft_dynset code allows local users to exhaust kernel memory through crafted set updates. The nft_dynset error path keeps the first stateful expression allocated when GFP_ATOMIC cloning of a second expression fails. Repeated reachable failures can consume kernel memory and interrupt service; exploitation requires local low-privileged access to configure nf_tables sets.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in the Linux Kernel nf_tables nft_dynset code allows local users to exhaust kernel memory through crafted set updates. The nft_dynset error path keeps the first stateful expression allocated when GFP_ATOMIC cloning of a second expression fails. Repeated reachable failures can consume kernel memory and interrupt service; exploitation requires local low-privileged access to configure nf_tables sets.

The record

CVE
CVE-2026-23399
Published
Mar 28, 2026
Updated
Mar 28, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-401, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.11
  2. Affected versionversion=563125a73ac30d7036ae69ca35c40500562c1de4 <0548a13b5a145b16e4da0628b5936baf35f51b43
  3. Affected versionversion=563125a73ac30d7036ae69ca35c40500562c1de4 <31641c682db73353e4647e40735c7f2a75ff58ef
  4. Affected versionversion=563125a73ac30d7036ae69ca35c40500562c1de4 <c88a9fd26cee365bec932196f76175772a941cca
  5. Affected versionversion=563125a73ac30d7036ae69ca35c40500562c1de4 <d1354873cbe3b344899c4311ac05897fd83e3f21

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.11; version=563125a73ac30d7036ae69ca35c40500562c1de4 <0548a13b5a145b16e4da0628b5936baf35f51b43; version=563125a73ac30d7036ae69ca35c40500562c1de4 <31641c682db73353e4647e40735c7f2a75ff58ef; version=563125a73ac30d7036ae69ca35c40500562c1de4 <c88a9fd26cee365bec932196f76175772a941cca; version=563125a73ac30d7036ae69ca35c40500562c1de4 <d1354873cbe3b344899c4311ac05897fd83e3f21

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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