CVE-2023-53088

Local privilege escalation via MPTCP listener shutdown

Published May 2, 2025 · Updated Aug 5, 2026

Use-after-free in Linux kernel MPTCP listener shutdown allows local users to escalate privileges through crafted socket operations. The close path drops the final MPTCP socket reference before inet_csk_listen_stop accesses it, allowing the grace period to expire and leaving a dangling subflow reference. Any unprivileged account able to create MPTCP sockets can reach the race, resulting in kernel memory compromise or a system crash.

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 listener shutdown allows local users to escalate privileges through crafted socket operations. The close path drops the final MPTCP socket reference before inet_csk_listen_stop accesses it, allowing the grace period to expire and leaving a dangling subflow reference. Any unprivileged account able to create MPTCP sockets can reach the race, resulting in kernel memory compromise or a system crash.

The record

CVE
CVE-2023-53088
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=5.18.10 <5.19
  2. Affected versionversion=5.19
  3. Affected versionversion=6aeed9045071f2252ff4e98fc13d1e304f33e5b0 <0a3f4f1f9c27215e4ddcd312558342e57b93e518
  4. Affected versionversion=6aeed9045071f2252ff4e98fc13d1e304f33e5b0 <0f4f4cf5d32f10543deb946a37111e714579511e
  5. Affected versionversion=6aeed9045071f2252ff4e98fc13d1e304f33e5b0 <5564be74a22a61855f8b8c100d8c4abb003bb792
  6. Affected versionversion=a8a3e95c74e48c2c9b07b81fafda9122993f2e12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.18.10 <5.19; version=5.19; version=6aeed9045071f2252ff4e98fc13d1e304f33e5b0 <0a3f4f1f9c27215e4ddcd312558342e57b93e518; version=6aeed9045071f2252ff4e98fc13d1e304f33e5b0 <0f4f4cf5d32f10543deb946a37111e714579511e; version=6aeed9045071f2252ff4e98fc13d1e304f33e5b0 <5564be74a22a61855f8b8c100d8c4abb003bb792; version=a8a3e95c74e48c2c9b07b81fafda9122993f2e12

Published CVSS scores

7.8Linux kernel CVE teamCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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.

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)
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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