CVE-2025-40271Public exploit

Kernel memory corruption via stale procfs node

Published Dec 6, 2025 · Updated Aug 5, 2026

Use-after-free in Linux procfs allows local users to access freed kernel memory by racing directory reads with network-device removal. proc_readdir_de() follows an erased red-black-tree node because rb_erase() leaves it nonempty, so pde_subdir_next() returns a freed proc entry. The race requires concurrent getdents traversal of /proc/pid/net/dev_snmp6 and removal of multiple tun devices, enabling kernel memory corruption or a crash.

CVSS severity7.8
High
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Use-after-free in Linux procfs allows local users to access freed kernel memory by racing directory reads with network-device removal. proc_readdir_de() follows an erased red-black-tree node because rb_erase() leaves it nonempty, so pde_subdir_next() returns a freed proc entry. The race requires concurrent getdents traversal of /proc/pid/net/dev_snmp6 and removal of multiple tun devices, enabling kernel memory corruption or a crash.

The record

CVE
CVE-2025-40271
Published
Dec 6, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-625, CWE-825, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 6, 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=3.19
  2. Affected versionversion=710585d4922fd315f2cada8fbe550ae8ed23e994 <03de7ff197a3d0e17d0d5c58fdac99a63cba8110
  3. Affected versionversion=710585d4922fd315f2cada8fbe550ae8ed23e994 <1d1596d68a6f11d28f677eedf6cf5b17dbfeb491
  4. Affected versionversion=710585d4922fd315f2cada8fbe550ae8ed23e994 <4cba73c4c89219beef7685a47374bf88b1022369
  5. Affected versionversion=710585d4922fd315f2cada8fbe550ae8ed23e994 <623bb26127fb581a741e880e1e1a47d79aecb6f8
  6. Affected versionversion=710585d4922fd315f2cada8fbe550ae8ed23e994 <67272c11f379d9aa5e0f6b16286b9d89b3f76046
  7. Affected versionversion=710585d4922fd315f2cada8fbe550ae8ed23e994 <6f2482745e510ae1dacc9b090194b9c5f918d774
  8. Affected versionversion=710585d4922fd315f2cada8fbe550ae8ed23e994 <895b4c0c79b092d732544011c3cecaf7322c36a1
  9. Affected versionversion=710585d4922fd315f2cada8fbe550ae8ed23e994 <c81d0385500446efe48c305bbb83d47f2ae23a50

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.19; version=710585d4922fd315f2cada8fbe550ae8ed23e994 <03de7ff197a3d0e17d0d5c58fdac99a63cba8110; version=710585d4922fd315f2cada8fbe550ae8ed23e994 <1d1596d68a6f11d28f677eedf6cf5b17dbfeb491; version=710585d4922fd315f2cada8fbe550ae8ed23e994 <4cba73c4c89219beef7685a47374bf88b1022369; version=710585d4922fd315f2cada8fbe550ae8ed23e994 <623bb26127fb581a741e880e1e1a47d79aecb6f8; version=710585d4922fd315f2cada8fbe550ae8ed23e994 <67272c11f379d9aa5e0f6b16286b9d89b3f76046; version=710585d4922fd315f2cada8fbe550ae8ed23e994 <6f2482745e510ae1dacc9b090194b9c5f918d774; version=710585d4922fd315f2cada8fbe550ae8ed23e994 <895b4c0c79b092d732544011c3cecaf7322c36a1; version=710585d4922fd315f2cada8fbe550ae8ed23e994 <c81d0385500446efe48c305bbb83d47f2ae23a50
Siemens · RUGGEDCOM RST2428Pversion=0 <V4.0

Published CVSS scores

7.0Siemens ProductCERTCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8LinuxCVSS: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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-625Permissive Regular Expression
CWE-825Expired Pointer Dereference
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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo