PT-2026-36457 · Linux · Linux Kernel

Published 2026-05-01 · Updated 2026-05-02 · CVE-2026-43040

Positive Technologies (AI Summary)

CVSS v3.1

7.1

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An information leak exists when processing Router Advertisements with user options. The kernel constructs an 'RTM NEWNDUSEROPT' netlink message using the nduseroptmsg struct, which contains three padding fields (nduseropt padX) that are not initialized to zero, potentially exposing kernel data.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Weakness Enumeration

CWE-909

Related Identifiers

CVE-2026-43040

ECHO-CEDF-49EC-FDFA

Affected Products

Linux Kernel

References · 18

• https://git.kernel.org/stable/c/1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c · Patch
• https://git.kernel.org/stable/c/ae05340ccaa9d347fe85415609e075545bec589f · Patch
• https://ubuntu.com/security/CVE-2026-43040 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-43040 · Security Note
• https://git.kernel.org/stable/c/11d7fe97421cfc81549940c20ed5ac9472d6db05 · Patch
• https://git.kernel.org/stable/c/7f56d87e527bb5a13c3e8b0d5840cb6332822f6d · Patch
• https://security-tracker.debian.org/tracker/CVE-2026-43040 · Vendor Advisory
• https://osv.dev/vulnerability/BELL-CVE-2026-43040 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-43040 · Vendor Advisory
• https://git.kernel.org/stable/c/2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648 · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-43040 · Vendor Advisory
• https://git.kernel.org/stable/c/4f810c686fde509d1cdaa706322d9d2531f8f1a4 · Patch
• https://git.kernel.org/stable/c/ef3645606e4a635d5062a492f22b7f490852ee67 · Patch
• https://git.kernel.org/stable/c/b485eef3d97b7aae55ce669b6de555ec81f3d21c · Patch
• https://cve.org/CVERecord?id=CVE-2026-43040 · Security Note