CVE-2024-40931

Local denial of service via uninitialized snd_una

Published Jul 12, 2024 · Updated May 11, 2026

Use of an uninitialized resource in the Linux kernel allows local users to interrupt the system by triggering an MPTCP retransmission. Following connection fallback, the retransmission path processes snd_una before any incoming packet initializes it, corrupting MPTCP acknowledgment state. A low-privileged local user must create the fallback-and-retransmit sequence; the reported consequence is availability loss without data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of an uninitialized resource in the Linux kernel allows local users to interrupt the system by triggering an MPTCP retransmission. Following connection fallback, the retransmission path processes snd_una before any incoming packet initializes it, corrupting MPTCP acknowledgment state. A low-privileged local user must create the fallback-and-retransmit sequence; the reported consequence is availability loss without data disclosure or modification.

The record

CVE
CVE-2024-40931
Published
Jul 12, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-908, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 12, 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 <208cd22ef5e57f82d38ec11c1a1703f9401d6dde
  3. Affected versionversion=8fd738049ac3d67a937d36577763b47180aae1ad <7b9c7fc8600b64a86e4b47b2d190bba380267726
  4. Affected versionversion=8fd738049ac3d67a937d36577763b47180aae1ad <8031b58c3a9b1db3ef68b3bd749fbee2e1e1aaa3
  5. Affected versionversion=8fd738049ac3d67a937d36577763b47180aae1ad <ef473bf1dd7e8dd08bcc04b9e2d1bfed69a0a7ce
  6. Affected versionversion=8fd738049ac3d67a937d36577763b47180aae1ad <f03c46eabb3a67bd2993e237ab5517f00a5f1813
  7. Affected versionversion=8fd738049ac3d67a937d36577763b47180aae1ad <f1f0a46f8bb8890b90ab7194f0a0c8fe2a3fb57f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.9; version=8fd738049ac3d67a937d36577763b47180aae1ad <208cd22ef5e57f82d38ec11c1a1703f9401d6dde; version=8fd738049ac3d67a937d36577763b47180aae1ad <7b9c7fc8600b64a86e4b47b2d190bba380267726; version=8fd738049ac3d67a937d36577763b47180aae1ad <8031b58c3a9b1db3ef68b3bd749fbee2e1e1aaa3; version=8fd738049ac3d67a937d36577763b47180aae1ad <ef473bf1dd7e8dd08bcc04b9e2d1bfed69a0a7ce; version=8fd738049ac3d67a937d36577763b47180aae1ad <f03c46eabb3a67bd2993e237ab5517f00a5f1813; version=8fd738049ac3d67a937d36577763b47180aae1ad <f1f0a46f8bb8890b90ab7194f0a0c8fe2a3fb57f

Published CVSS scores

5.5NIST NVDCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-908Use of Uninitialized Resource
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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