CVE-2025-40170

Kernel compromise via unprotected route-device access

Published Nov 12, 2025 · Updated Aug 5, 2026

Use-after-free in Linux allows local users to compromise kernel confidentiality, integrity, and availability through affected networking paths. sk_setup_caps and related MTU and hop-limit helpers dereference dst->dev without RCU protection while the destination device can be released concurrently. Exploitation requires low local privileges and a route-device lifetime race; success can expose or alter kernel data or crash the system.

CVSS severity7.8
High
EPSS probability0.15%
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 compromise kernel confidentiality, integrity, and availability through affected networking paths. sk_setup_caps and related MTU and hop-limit helpers dereference dst->dev without RCU protection while the destination device can be released concurrently. Exploitation requires low local privileges and a route-device lifetime race; success can expose or alter kernel data or crash the system.

The record

CVE
CVE-2025-40170
Published
Nov 12, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
Unavailable

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

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=4.13
  2. Affected versionversion=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <5d1be493d1110c9e720b4c51a6e587bb2fb4ac12
  3. Affected versionversion=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <99a2ace61b211b0be861b07fbaa062fca4b58879
  4. Affected versionversion=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <a805729c0091073d8f0415cfa96c7acd1bc17a48

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=4.13; version=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <5d1be493d1110c9e720b4c51a6e587bb2fb4ac12; version=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <99a2ace61b211b0be861b07fbaa062fca4b58879; version=4a6ce2b6f2ecabbddcfe47e7cf61dd0f00b10e36 <a805729c0091073d8f0415cfa96c7acd1bc17a48

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.

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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