In the Linux kernel, the following vulnerability has been resolved: net: ipv6: ndisc: fix...

CVE-2026-43040 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

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.

Basic information

Type
unreviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
—
Source code
Not specified
Published (advisory)
2026-05-01 15:30:37 UTC
Updated
2026-07-14 15:31:58 UTC
NVD published
2026-05-01

EPSS Score

Score Percentile
0.12% 2.37%

CVSS Scores

Base score Version Severity Vector
7.1 3.1 —
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.

Identifiers

Type Value
GHSA GHSA-59pc-r9mr-h2pv ↗
CVE CVE-2026-43040 ↗

CWEs

CWE id Name
CWE-909 Missing Initialization of Resource

References

cvelogic Threat Intelligence