CVE-2023-53072

Local kernel memory corruption via MPTCP socket cleanup

Published May 2, 2025 · Updated Aug 5, 2026

Use-after-free in Linux kernel MPTCP 5.7 through 6.1.21 and 6.2 through 6.2.7 allows local users to access freed kernel memory. MPTCP cleanup releases an unaccepted master socket before a paired subflow finishes, leaving token lookup to read the freed socket in __token_bucket_busy. Exploitation requires local low-privileged access and an MPTCP fast-open send path; token lookup then reads freed kernel memory.

CVSS severity7.8
High
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux kernel MPTCP 5.7 through 6.1.21 and 6.2 through 6.2.7 allows local users to access freed kernel memory. MPTCP cleanup releases an unaccepted master socket before a paired subflow finishes, leaving token lookup to read the freed socket in __token_bucket_busy. Exploitation requires local low-privileged access and an MPTCP fast-open send path; token lookup then reads freed kernel memory.

The record

CVE
CVE-2023-53072
Published
May 2, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=5.7
  2. Affected versionversion=58b09919626bf9067345289212ec030c61eb1034 <2827f099b3fb9a59263c997400e9182f5d423e84
  3. Affected versionversion=58b09919626bf9067345289212ec030c61eb1034 <804cf487fb0031f3c74755b78d8663333f0ba636
  4. Affected versionversion=58b09919626bf9067345289212ec030c61eb1034 <b6985b9b82954caa53f862d6059d06c0526254f0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.7; version=58b09919626bf9067345289212ec030c61eb1034 <2827f099b3fb9a59263c997400e9182f5d423e84; version=58b09919626bf9067345289212ec030c61eb1034 <804cf487fb0031f3c74755b78d8663333f0ba636; version=58b09919626bf9067345289212ec030c61eb1034 <b6985b9b82954caa53f862d6059d06c0526254f0

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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-416Use After Free
T1068Exploitation for Privilege Escalation

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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