CVE-2024-36889

Service interruption via uninitialized MPTCP sequence state

Published May 30, 2024 · Updated May 11, 2026

Improper initialization in affected Linux kernels allows local users to trigger a service interruption through MPTCP. During early TCP fallback, net/mptcp/protocol.c leaves snd_nxt uninitialized, copies it into snd_una on an ACK, and cleans the send buffer with the corrupted value. The path requires an MPTCP client connection to fall back early to TCP and enter re-injection; the observed result is a kernel warning, and upstream describes practical impact as very low to zero.

CVSS severity5.5
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper initialization in affected Linux kernels allows local users to trigger a service interruption through MPTCP. During early TCP fallback, net/mptcp/protocol.c leaves snd_nxt uninitialized, copies it into snd_una on an ACK, and cleans the send buffer with the corrupted value. The path requires an MPTCP client connection to fall back early to TCP and enter re-injection; the observed result is a kernel warning, and upstream describes practical impact as very low to zero.

The record

CVE
CVE-2024-36889
Published
May 30, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-665, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 30, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=5.9
  2. Affected versionversion=8fd738049ac3d67a937d36577763b47180aae1ad <39ca83ed73db9edcc6d70c0dc7a73085a4725012
  3. Affected versionversion=8fd738049ac3d67a937d36577763b47180aae1ad <592f69b41766d366dbb8ff4ef5a67c4396527bbe
  4. Affected versionversion=8fd738049ac3d67a937d36577763b47180aae1ad <99951b62bf20cec9247f633a3bea898338b9e5b4
  5. Affected versionversion=8fd738049ac3d67a937d36577763b47180aae1ad <aa0c07c1f20e05b30019bff083ec43665536f06f
  6. Affected versionversion=8fd738049ac3d67a937d36577763b47180aae1ad <dc941fec0719d0471a5902424d6b2a17df233193
  7. Affected versionversion=8fd738049ac3d67a937d36577763b47180aae1ad <fb7a0d334894206ae35f023a82cad5a290fd7386

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.9; version=8fd738049ac3d67a937d36577763b47180aae1ad <39ca83ed73db9edcc6d70c0dc7a73085a4725012; version=8fd738049ac3d67a937d36577763b47180aae1ad <592f69b41766d366dbb8ff4ef5a67c4396527bbe; version=8fd738049ac3d67a937d36577763b47180aae1ad <99951b62bf20cec9247f633a3bea898338b9e5b4; version=8fd738049ac3d67a937d36577763b47180aae1ad <aa0c07c1f20e05b30019bff083ec43665536f06f; version=8fd738049ac3d67a937d36577763b47180aae1ad <dc941fec0719d0471a5902424d6b2a17df233193; version=8fd738049ac3d67a937d36577763b47180aae1ad <fb7a0d334894206ae35f023a82cad5a290fd7386

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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-665Improper Initialization
T1499Endpoint Denial of Service

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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