CVE-2026-43040
kernel: net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 1, 2026
Updated · June 28, 2026
Description
A flaw was found in the Linux kernel. When processing Router Advertisements with user options, the nduseroptmsg structure's padding fields are not properly zeroed. This oversight can lead to an information leak, potentially exposing sensitive kernel data. A remote attacker could exploit this to gain unauthorized access to system information.
Statement
IPv6 RA user options must zero pad fields to avoid leaking uninitialized kernel memory in /proc netlink readers. Red Hat classifies this as C:L info leak hardening for ndisc useropt output.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-909 · Missing Initialization of Resource