CVE-2025-40158Network attack vector

Kernel memory corruption via IPv6 device race

Published Nov 12, 2025 · Updated Aug 5, 2026

Use-after-free in the Linux kernel IPv6 output path from 4.13 through 6.17.2 allows remote attackers to corrupt kernel memory. ip6_output() obtains and dereferences the destination network device without an encompassing RCU read-side critical section, allowing concurrent device release to leave a stale pointer. Exploitation requires forwarded IPv6 traffic to coincide with a network-device lifetime change; the resulting access can crash the kernel or corrupt memory.

CVSS severity8.1
High
EPSS probability0.44%
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 Linux kernel IPv6 output path from 4.13 through 6.17.2 allows remote attackers to corrupt kernel memory. ip6_output() obtains and dereferences the destination network device without an encompassing RCU read-side critical section, allowing concurrent device release to leave a stale pointer. Exploitation requires forwarded IPv6 traffic to coincide with a network-device lifetime change; the resulting access can crash the kernel or corrupt memory.

The record

CVE
CVE-2025-40158
Published
Nov 12, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 12, 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=4.13
  2. Affected versionversion=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <0393f85c3241c19ba8550f04a812e7d19f6b3082
  3. Affected versionversion=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <11709573cc4e48dc34c80fc7ab9ce5b159e29695

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.13; version=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <0393f85c3241c19ba8550f04a812e7d19f6b3082; version=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <11709573cc4e48dc34c80fc7ab9ce5b159e29695

Published CVSS scores

8.1Linux CNACVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
7.0OracleCVSS: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.

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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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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