Linux Kernel up to 6.1.160/6.6.120/6.12.65/6.18.5 netfilter nf_conncount last_gc resource consumption

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 6.1.160/6.6.120/6.12.65/6.18.5. This issue affects the function nf_conncount of the component netfilter. The manipulation of the argument last_gc results in resource consumption. This vulnerability is known as CVE-2026-23139. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.160/6.6.120/6.12.65/6.18.5. It has been classified as critical. Affected is the function nf_conncount of the component netfilter. The manipulation of the argument last_gc with an unknown input leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conncount: update last_gc only when GC has been performed Currently last_gc is being updated everytime a new connection is tracked, that means that it is updated even if a GC wasn't performed. With a sufficiently high packet rate, it is possible to always bypass the GC, causing the list to grow infinitely. Update the last_gc value only when a GC has been actually performed.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-23139 since 01/13/2026. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 299224 (Linux Distros Unpatched Vulnerability : CVE-2026-23139), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.161, 6.6.121, 6.12.66 or 6.18.6 eliminates this vulnerability. Applying the patch 2c7c71113ed6d3e2f3aca4c088f22283016ff34f/c4cde57c8affdcca5bcff53a1047e15d268bdca1/9f45588993d7f115280fc726119ca86fba32a811/3cd717359e56f82f06cbf8279b47a7d79880c6f3/26a82dce2beee39c43c109d9647e16f49cb02a35/8bdafdf4900040a81422056cabe5e00a37bd101a/7811ba452402d58628e68faedf38745b3d485e3c is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (299224). Once again VulDB remains the best source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Resource consumption
CWE: CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 299224
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-23139

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.161/6.6.121/6.12.66/6.18.6
Patch: 2c7c71113ed6d3e2f3aca4c088f22283016ff34f/c4cde57c8affdcca5bcff53a1047e15d268bdca1/9f45588993d7f115280fc726119ca86fba32a811/3cd717359e56f82f06cbf8279b47a7d79880c6f3/26a82dce2beee39c43c109d9647e16f49cb02a35/8bdafdf4900040a81422056cabe5e00a37bd101a/7811ba452402d58628e68faedf38745b3d485e3c

Timelineinfo

01/13/2026 CVE reserved
02/14/2026 +32 days Advisory disclosed
02/14/2026 +0 days VulDB entry created
03/18/2026 +32 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-23139 (🔒)
GCVE (CVE): GCVE-0-2026-23139
GCVE (VulDB): GCVE-100-346020

Entryinfo

Created: 02/14/2026 17:53
Updated: 03/18/2026 02:15
Changes: 02/14/2026 17:53 (60), 02/17/2026 04:37 (2), 02/19/2026 10:00 (1), 03/18/2026 02:15 (10)
Complete: 🔍
Cache ID: 216::103

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