CyberSecBulletin
CVE-2026-43040NVD status: Modified

Linux: Missing Initialization of Resource

Published Updated By the CyberSecBulletin desk

CVE-2026-43040 is a high-severity missing initialization of resource vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c, 2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648, 11d7fe97421cfc81549940c20ed5ac9472d6db05 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.13% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c or 2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648 or 11d7fe97421cfc81549940c20ed5ac9472d6db05 or 7f56d87e527bb5a13c3e8b0d5840cb6332822f6d, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.253 or 5.15.203 or 6.1.168 or 6.6.134, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux31910575a9de61e78065e93846e8e7a4894a18bf up to, but not including, 1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c; 31910575a9de61e78065e93846e8e7a4894a18bf up to, but not including, 2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648; 31910575a9de61e78065e93846e8e7a4894a18bf up to, but not including, 11d7fe97421cfc81549940c20ed5ac9472d6db05; 31910575a9de61e78065e93846e8e7a4894a18bf up to, but not including, 7f56d87e527bb5a13c3e8b0d5840cb6332822f6d; 31910575a9de61e78065e93846e8e7a4894a18bf up to, but not including, 4f810c686fde509d1cdaa706322d9d2531f8f1a4; 31910575a9de61e78065e93846e8e7a4894a18bf up to, but not including, b485eef3d97b7aae55ce669b6de555ec81f3d21c; 31910575a9de61e78065e93846e8e7a4894a18bf up to, but not including, ef3645606e4a635d5062a492f22b7f490852ee67; 31910575a9de61e78065e93846e8e7a4894a18bf up to, but not including, ae05340ccaa9d347fe85415609e075545bec589f; and 1 more ranges1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c, 2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648, 11d7fe97421cfc81549940c20ed5ac9472d6db05, 7f56d87e527bb5a13c3e8b0d5840cb6332822f6d, 4f810c686fde509d1cdaa706322d9d2531f8f1a4, b485eef3d97b7aae55ce669b6de555ec81f3d21c
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
SiemensSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
LinuxLinux Kernel2.6.24 up to, but not including, 5.10.253; 5.11 up to, but not including, 5.15.203; 5.16 up to, but not including, 6.1.168; 6.2 up to, but not including, 6.6.134; 6.7 up to, but not including, 6.12.81; 6.13 up to, but not including, 6.18.22; 6.19 up to, but not including, 6.19.12; 7.05.10.253, 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak When processing Router Advertisements with user options the kernel builds an RTM_NEWNDUSEROPT netlink message. The nduseroptmsg struct has three padding fields that are never zeroed and can leak kernel data The fix is simple, just zeroes the padding fields.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Missing Initialization of Resource

The product does not initialize a critical resource.

How developers prevent this class of flaw

  • Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all specified steps.
  • Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
  • Avoid race conditions (CWE-362) during initialization routines.

More Missing Initialization of Resource vulnerabilities (CWE-909)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Missing Initialization of Resource vulnerabilities

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