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7.1
HIGH CVSS 3.1
CVE-2026-31407
netfilter: conntrack: add missing netlink policy validations
Overview
Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: add missing netlink policy validations Hyunwoo Kim reports out-of-bounds access in sctp and ctnetlink. These attributes are used by the kernel without any validation. Extend the netlink policies accordingly. Quoting the reporter: nlattr_to_sctp() assigns the user-supplied CTA_PROTOINFO_SCTP_STATE value directly to ct->proto.sctp.state without checking that it is within the valid range. [..] and: ... with exp->dir = 100, the access at ct->master->tuplehash[100] reads 5600 bytes past the start of a 320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by UBSAN.

Details
INFO

Published Date :

April 6, 2026, 8:16 a.m.

Last Modified :

April 27, 2026, 2:16 p.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Impact
Affected Products

The following products are affected by CVE-2026-31407 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
Add netlink policy validations to prevent out-of-bounds access in netfilter.
  • Validate user-supplied attributes before use.
  • Update netlink policies for ctnetlink.
  • Apply patch for netfilter: conntrack: add missing netlink policy validations.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-31407.

URL Resource
https://git.kernel.org/stable/c/0fbae1e74493d5a160a70c51aeba035d8266ea7d
https://git.kernel.org/stable/c/67c53c1978cef3c504237275e39c857e2f6af56e
https://git.kernel.org/stable/c/9174d28f3f15d8c4962f5980c0be167633880443
https://git.kernel.org/stable/c/c5e918390002edf0cff80a0e7ce1f86f16a9507c
https://git.kernel.org/stable/c/f900e1d77ee0ef87bfb5ab3fe60f0b3d8ad5ba05
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-31407 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-31407 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-31407 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-31407 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Apr. 27, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
    Added Reference https://git.kernel.org/stable/c/c5e918390002edf0cff80a0e7ce1f86f16a9507c
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Apr. 22, 2026

    Action Type Old Value New Value
    Added Reference https://git.kernel.org/stable/c/67c53c1978cef3c504237275e39c857e2f6af56e
    Added Reference https://git.kernel.org/stable/c/9174d28f3f15d8c4962f5980c0be167633880443
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Apr. 06, 2026

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: add missing netlink policy validations Hyunwoo Kim reports out-of-bounds access in sctp and ctnetlink. These attributes are used by the kernel without any validation. Extend the netlink policies accordingly. Quoting the reporter: nlattr_to_sctp() assigns the user-supplied CTA_PROTOINFO_SCTP_STATE value directly to ct->proto.sctp.state without checking that it is within the valid range. [..] and: ... with exp->dir = 100, the access at ct->master->tuplehash[100] reads 5600 bytes past the start of a 320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by UBSAN.
    Added Reference https://git.kernel.org/stable/c/0fbae1e74493d5a160a70c51aeba035d8266ea7d
    Added Reference https://git.kernel.org/stable/c/f900e1d77ee0ef87bfb5ab3fe60f0b3d8ad5ba05
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 7.1
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact