CVE-2023-53720

Kernel memory leak via unreleased conntrack labels

Published Oct 22, 2025 · Updated Oct 22, 2025

Resource leak in Linux kernel 6.3 before 6.3.2 allows attackers to consume kernel memory via replaced mlx5e conntrack entries. In drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c, the replacement path obtains a label mapping but fails to release the existing entry's mapping. Reachability requires the mlx5e traffic-control connection-tracking offload path; the published record demonstrates a kernel-memory leak but documents neither a crash nor an attacker privilege requirement.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource leak in Linux kernel 6.3 before 6.3.2 allows attackers to consume kernel memory via replaced mlx5e conntrack entries. In drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c, the replacement path obtains a label mapping but fails to release the existing entry's mapping. Reachability requires the mlx5e traffic-control connection-tracking offload path; the published record demonstrates a kernel-memory leak but documents neither a crash nor an attacker privilege requirement.

The record

CVE
CVE-2023-53720
Published
Oct 22, 2025
Updated
Oct 22, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 22, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 22, 2025Record 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=6.3
  2. Affected versionversion=94ceffb48eac7692677d8093dcde6965b70c4b35 <3db903a71f1f4bbf30baae166a4a49f2e8aceb61
  3. Affected versionversion=94ceffb48eac7692677d8093dcde6965b70c4b35 <8ac04a28144cfa89b61be518268233742c23d88d

What conditions does exploitation require?

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

What is affected?

The Linux Kernel Organization · Linuxversion=6.3; version=94ceffb48eac7692677d8093dcde6965b70c4b35 <3db903a71f1f4bbf30baae166a4a49f2e8aceb61; version=94ceffb48eac7692677d8093dcde6965b70c4b35 <8ac04a28144cfa89b61be518268233742c23d88d

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.

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

No observations available

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

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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