High 7.1Published May 1, 2026

CVE-2026-43040net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak

Updated under an hour ago (Oct 26, 2026, 8:40 PM ET)

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Exploited in the last 30 days

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.

CVSS: 7.1 HIGH (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	31910575a9de61e78065e93846e8e7a4894a18bf builds before 1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c; 31910575a9de61e78065e93846e8e7a4894a18bf builds before 2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648; 31910575a9de61e78065e93846e8e7a4894a18bf builds before 11d7fe97421cfc81549940c20ed5ac9472d6db05; 31910575a9de61e78065e93846e8e7a4894a18bf builds before 7f56d87e527bb5a13c3e8b0d5840cb6332822f6d; 31910575a9de61e78065e93846e8e7a4894a18bf builds before 4f810c686fde509d1cdaa706322d9d2531f8f1a4; from 31910575a9de61e78065e93846e8e7a4894a18bf before b485eef3d97b7aae55ce669b6de555ec81f3d21c; from 31910575a9de61e78065e93846e8e7a4894a18bf before ef3645606e4a635d5062a492f22b7f490852ee67; from 31910575a9de61e78065e93846e8e7a4894a18bf before ae05340ccaa9d347fe85415609e075545bec589f	CNA record
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
linux linux_kernel linux:linux_kernel	from 2.6.24 before 5.10.253; from 5.11 before 5.15.203; from 5.16 before 6.1.168; from 6.2 before 6.6.134; from 6.7 before 6.12.81; from 6.13 before 6.18.22; from 6.19 before 6.19.12; 7.0; and 5 more ranges	NVD

References

References

https://git.kernel.org/stable/c/1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c	patch
https://git.kernel.org/stable/c/2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648	patch
https://git.kernel.org/stable/c/11d7fe97421cfc81549940c20ed5ac9472d6db05	patch
https://git.kernel.org/stable/c/7f56d87e527bb5a13c3e8b0d5840cb6332822f6d	patch
https://git.kernel.org/stable/c/4f810c686fde509d1cdaa706322d9d2531f8f1a4	patch
https://git.kernel.org/stable/c/b485eef3d97b7aae55ce669b6de555ec81f3d21c	patch
https://git.kernel.org/stable/c/ef3645606e4a635d5062a492f22b7f490852ee67	patch
https://git.kernel.org/stable/c/ae05340ccaa9d347fe85415609e075545bec589f	patch
https://cert-portal.siemens.com/productcert/html/ssa-019113.html
https://cert-portal.siemens.com/productcert/html/ssa-082556.html
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.