CVE-2026-31663

Kernel memory corruption via premature device release

Published Apr 24, 2026 · Updated Apr 24, 2026

Use-after-free in the XFRM subsystem in affected Linux kernels allows local users to crash the kernel or corrupt kernel memory. After asynchronous crypto completion, xfrm_input_resume() drops the skb device reference before NF_HOOK and its callback finish using skb->dev, allowing device teardown to race with later access. An unprivileged local user must create user and network namespaces, configure transport-mode XFRM state, inject traffic, and race device teardown; exploitation can also expose kernel memory.

CVSS severity7.8
High
EPSS probability0.12%
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 the XFRM subsystem in affected Linux kernels allows local users to crash the kernel or corrupt kernel memory. After asynchronous crypto completion, xfrm_input_resume() drops the skb device reference before NF_HOOK and its callback finish using skb->dev, allowing device teardown to race with later access. An unprivileged local user must create user and network namespaces, configure transport-mode XFRM state, inject traffic, and race device teardown; exploitation can also expose kernel memory.

The record

CVE
CVE-2026-31663
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-826, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 24, 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=4.15
  2. Affected versionversion=69895c5ea0ca2e8d7de1e6d36965d0ab9730787f
  3. Affected versionversion=833760100588acfb267dac4d6a02ab9931237739
  4. Affected versionversion=acf568ee859f098279eadf551612f103afdacb4e <0f451b43c88bf2b9c038b414be580efee42e031b
  5. Affected versionversion=acf568ee859f098279eadf551612f103afdacb4e <1c428b03840094410c5fb6a5db30640486bbbfcb
  6. Affected versionversion=acf568ee859f098279eadf551612f103afdacb4e <5002beda5cac69d522dc54da0d5d463ed9c963d2
  7. Affected versionversion=e095ecaec6d94aa2156cceb98a85d409b51190f3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.15; version=69895c5ea0ca2e8d7de1e6d36965d0ab9730787f; version=833760100588acfb267dac4d6a02ab9931237739; version=acf568ee859f098279eadf551612f103afdacb4e <0f451b43c88bf2b9c038b414be580efee42e031b; version=acf568ee859f098279eadf551612f103afdacb4e <1c428b03840094410c5fb6a5db30640486bbbfcb; version=acf568ee859f098279eadf551612f103afdacb4e <5002beda5cac69d522dc54da0d5d463ed9c963d2; version=e095ecaec6d94aa2156cceb98a85d409b51190f3

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
7.0UbuntuCVSS:3.1/AV:L/AC:H/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-826Premature Release of Resource During Expected Lifetime
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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