CVE-2026-43040: net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak
In the Linux kernel, the following vulnerability has been resolved:
net: ipv6: ndisc: fix ndiscrauseropt to initialize nduseroptpadX fields to zero to prevent an info-leak
When processing Router Advertisements with user options the kernel builds an RTMNEWNDUSEROPT 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.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-43040?
CVE-2026-43040 has been assessed with a severity rating that indicates it could lead to an information leak due to incomplete initialization in the Linux kernel's ndisc_ra_useropt.
How does CVE-2026-43040 affect the Linux kernel?
CVE-2026-43040 affects the Linux kernel by allowing nduseropt_padX fields to remain uninitialized, potentially exposing sensitive information.
How do I fix CVE-2026-43040?
To remediate CVE-2026-43040, update to the latest version of the Linux kernel that includes the patch addressing this vulnerability.
What systems are affected by CVE-2026-43040?
CVE-2026-43040 impacts systems running vulnerable versions of the Linux kernel that utilize IPv6 and ndisc functions.
Is CVE-2026-43040 a remote exploit?
CVE-2026-43040 does not constitute a remote exploit but rather a local info-leak vulnerability related to improperly initialized fields.