CVE-2026-98321

Kernel memory leak via failed NAT hook insertion

Published Oct 6, 2026 · Updated Oct 6, 2026

A memory leak in Linux kernel 4.18 nf_nat leaves NAT hooks allocated when hook insertion fails during registration. The nf_nat_register_fn error path does not unregister the base NAT hooks or release their allocations after nf_hook_entries_insert_raw fails. The leak requires NAT hook registration and a failed insertion; the upstream fix does not establish that remote traffic alone can trigger it.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Oct 18, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A memory leak in Linux kernel 4.18 nf_nat leaves NAT hooks allocated when hook insertion fails during registration. The nf_nat_register_fn error path does not unregister the base NAT hooks or release their allocations after nf_hook_entries_insert_raw fails. The leak requires NAT hook registration and a failed insertion; the upstream fix does not establish that remote traffic alone can trigger it.

The record

CVE
CVE-2026-98321
Published
Oct 6, 2026
Updated
Oct 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 6, 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=1cd472bf036ca038e783ef5f058f54e45b7e8180 <79084567cd082fb4482e1ea457580e7d6504dd99
  2. Affected versionversion=1cd472bf036ca038e783ef5f058f54e45b7e8180 <cbdd39ce42530a193c56beb206a3356cb6d01016
  3. Affected versionversion=1cd472bf036ca038e783ef5f058f54e45b7e8180 <df80342f4bfc023ad7d6703df5e27f583ff0cb8d
  4. Affected versionversion=4.18

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=1cd472bf036ca038e783ef5f058f54e45b7e8180 <79084567cd082fb4482e1ea457580e7d6504dd99; version=1cd472bf036ca038e783ef5f058f54e45b7e8180 <cbdd39ce42530a193c56beb206a3356cb6d01016; version=1cd472bf036ca038e783ef5f058f54e45b7e8180 <df80342f4bfc023ad7d6703df5e27f583ff0cb8d; version=4.18

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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