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VulnerabilityPublished Updated

CVE-2025-40018: Linux kernel · ipvs: Defer ip_vs_ftp unregister during netns cleanup

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 7.8 High · fixed in 4.4.0-1150.156 : patch Linux kernel soon.

Data as of 28 Oct 2026, 11:19 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 4.4.0-1150.156, 4.15.0-1195.210~14.04.1, 4.4.0-276.310~14.04.1 +117
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 24 Oct 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threatsAffected
  • <6.17.0-8.8
Fixed in
  • 6.17.0-8.8
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1005.5
Fixed in
  • 6.17.0-1005.5
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1006.6
Fixed in
  • 6.17.0-1006.6
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threatsAffected
  • 6.17.0-1003.3 – 6.17.0-1017.17
10 affected builds
Fixed in–
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1005.5
Fixed in
  • 6.17.0-1005.5
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1005.5
Fixed in
  • 6.17.0-1005.5

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available and has been released in multiple Linux kernel versions as listed in the established fixed versions. Users should update their Linux kernel to one of the fixed versions to remediate this vulnerability. After applying the update, a system reboot is required to activate the fix. Additionally, due to ABI changes, recompilation and reinstallation of third-party kernel modules may be necessary. No other specific mitigations are indicated by the vendor advisory.

Description

CVE-2025-40018 is a use-after-free vulnerability in the Linux kernel's IP Virtual Server (ipvs) FTP module. The flaw occurs during network namespace cleanup when the ip_vs_ftp unregister function is called prematurely before all connections with valid application pointers are flushed. This can lead to memory corruption and potentially allow an attacker with local privileges to compromise system integrity. The issue has been fixed by deferring the unregister operation until all connections are properly cleaned up. Multiple Linux kernel versions are affected, and patches have been released.

References

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