CVE-2025-40018VulnerabilityPublished 2 Dec 2025Updated 31 Jul 2026

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

Affects linuxSource GCVE Database

Not known to be exploited · CVSS 7.8 High · fixed in 4.15.0-1195.210~14.04.1 : patch linux soon.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

7.8High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.15.0-1195.210~14.04.1, 4.4.0-1188.203, 4.4.0-1150.156 +2

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
linux	Affected <4.4.0-1150.156 <4.15.0-1195.210~14.04.1 <4.4.0-276.310~14.04.1 <4.4.0-276.310 <4.4.0-1188.203	Fixed in 4.4.0-1150.156 4.15.0-1195.210~14.04.1 4.4.0-276.310~14.04.1 4.4.0-276.310 4.4.0-1188.203

AI-suggested

A fix is available that introduces a global flag to defer ip_vs_ftp unregistering during network namespace cleanup until all connections are flushed. Users should apply the official Linux kernel updates that include this patch to remediate the vulnerability.

Description

Published: 2025-12-02 Updated: 2026-03-25 Reference: CVE-2025-40018 2026-03-25 Update: Added patch versions for Ubuntu nodes with GKE. 2025-12-11 Update: Added patch versions and a severity rating for GDC (VMware). GKE Updated: 2026-03-25 Description Severity The following vulnerabilities were discovered in the Linux kernel that can lead to a privilege escalation on Container-Optimized OS nodes: CVE-2025-40018 GKE Standard clusters are impacted. GKE Autopilot clusters in the default configuration are not impacted, but might be vulnerable if you explicitly set the seccomp Unconfined profile or allow CAP_NET_ADMIN . Clusters using GKE Sandbox aren't impacted. What should I do? 2026-03-25 Update : The following versions of GKE are updated with code to fix this vulnerability on Ubuntu. Upgrade your Ubuntu node pools to the following versions or later: 1.35.1-gke.1396000 1.34.4-gke.1047000 1.33.8-gke.1026000 1.32.12-gke.1026000 1.31.14-gke.1336000 1.30.14-gke.1991000 The following minor versions are affected. Upgrade your Container-Optimized OS node pools to one of the following patch versions or later: 1.32.9-gke.1330000 1.29.15-gke.2236000 1.30.14-gke.1525000 1.31.13-gke.1231000 1.34.1-gke.2541000 1.28.15-gke.2966000 1.33.5-gke.1350000 You can apply patch versions from newer release channels if your cluster runs the same minor version in its own release channel. This feature lets you secure your nodes until the patch version becomes the default in your release channel. For details, see Run patch versions from a newer channel . High GDC (VMware) Updated: 2025-12-11 Description Severity The following vulnerabilities were discovered in the Linux kernel that can lead to a privilege escalation on Container-Optimized OS nodes: CVE-2025-40018 What should I do? The following versions of GDC (VMware) are updated with code to fix this vulnerability. Upgrade your GDC (VMware) clusters to the following versions or later: 1.31.1100-gke.40 Note: Patch versions and a severity assessment for GDC software for VMware are in progress. We'll update this bulletin with that information when it's available. High GKE on AWS Description Severity The following vulnerabilities were discovered in the Linux kernel that can lead to a privilege escalation on Container-Optimized OS nodes: CVE-2025-40018 What should I do? Note: Patch versions and a severity assessment for GKE on AWS are in progress. We'll update this bulletin with that information when it's available. Pending GKE on Azure Description Severity The following vulnerabilities were discovered in the Linux kernel that can lead to a privilege escalation on Container-Optimized OS nodes: CVE-2025-40018 What should I do? Note: Patch versions and a severity assessment for GKE on Azure are in progress. We'll update this bulletin with that information when it's available. Pending GDC (bare metal) Description Severity The following vulnerabilities were discovered in the Linux kernel that can lead to a privilege escalation on Container-Optimized OS nodes: CVE-2025-40018 What should I do? There is no action required. GDC software for bare metal isn't affected as it does not bundle an operating system in its distribution. None

Impact

Successful exploitation could lead to use-after-free conditions, resulting in potential kernel memory corruption with high impact on confidentiality, integrity, and availability of the system. This could allow an attacker with local privileges to cause system crashes or execute arbitrary code within the kernel context.

Summary

CVE-2025-40018 addresses a use-after-free vulnerability in the Linux kernel's ip_vs_ftp module during network namespace (netns) cleanup. The issue arises because __ip_vs_ftp_exit() may unregister ip_vs_ftp before all connections with valid cp->app pointers are flushed, causing use-after-free conditions. The patch adds a global 'exiting_module' flag to defer unregistering during netns cleanup until all connections are flushed, preventing premature unregistering and memory corruption.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Jul 2026, 15:56 UTC

Technical details

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