CVE-2024-26921Public exploit

Kernel-memory corruption via premature socket release

Published Apr 18, 2024 · Updated Aug 5, 2026

Use-after-free in Linux allows local users to corrupt kernel memory by sending fragmented traffic through a configured transmit pipeline. During output-path reassembly, ip_defrag() orphans a fragmented skb too early, releases its socket, and leaves downstream code to dereference the stale skb->sk pointer. Exploitation requires local low-privileged access plus user-namespace networking capabilities; the demonstrated result is a kernel memory safety violation that can crash the host or support privilege escalation.

CVSS severity7.8
High
EPSS probability0.40%
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 allows local users to corrupt kernel memory by sending fragmented traffic through a configured transmit pipeline. During output-path reassembly, ip_defrag() orphans a fragmented skb too early, releases its socket, and leaves downstream code to dereference the stale skb->sk pointer. Exploitation requires local low-privileged access plus user-namespace networking capabilities; the demonstrated result is a kernel memory safety violation that can crash the host or support privilege escalation.

The record

CVE
CVE-2024-26921
Published
Apr 18, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 18, 2024CVE 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.1
  2. Affected versionversion=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <18685451fc4e546fc0e718580d32df3c0e5c8272
  3. Affected versionversion=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <1b6de5e6575b56502665c65cf93b0ae6aa0f51ab
  4. Affected versionversion=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <4318608dc28ef184158b4045896740716bea23f0
  5. Affected versionversion=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <7d0567842b78390dd9b60f00f1d8f838d540e325
  6. Affected versionversion=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <9705f447bf9a6cd088300ad2c407b5e1c6591091
  7. Affected versionversion=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <e09cbe017311508c21e0739e97198a8388b98981
  8. Affected versionversion=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <f4877225313d474659ee53150ccc3d553a978727

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.1; version=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <18685451fc4e546fc0e718580d32df3c0e5c8272; version=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <1b6de5e6575b56502665c65cf93b0ae6aa0f51ab; version=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <4318608dc28ef184158b4045896740716bea23f0; version=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <7d0567842b78390dd9b60f00f1d8f838d540e325; version=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <9705f447bf9a6cd088300ad2c407b5e1c6591091; version=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <e09cbe017311508c21e0739e97198a8388b98981; version=7026b1ddb6b8d4e6ee33dc2bd06c0ca8746fa7ab <f4877225313d474659ee53150ccc3d553a978727

Published CVSS scores

7.8Linux kernel CNACVSS: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 exploitPublished

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

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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