CVE-2026-43040 PUBLISHED

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

Assigner: Linux
Reserved: 01.05.2026 Published: 01.05.2026 Updated: 01.05.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 31910575a9de61e78065e93846e8e7a4894a18bf to 1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c (excl.)
  • affected from 31910575a9de61e78065e93846e8e7a4894a18bf to 2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648 (excl.)
  • affected from 31910575a9de61e78065e93846e8e7a4894a18bf to 11d7fe97421cfc81549940c20ed5ac9472d6db05 (excl.)
  • affected from 31910575a9de61e78065e93846e8e7a4894a18bf to 7f56d87e527bb5a13c3e8b0d5840cb6332822f6d (excl.)
  • affected from 31910575a9de61e78065e93846e8e7a4894a18bf to 4f810c686fde509d1cdaa706322d9d2531f8f1a4 (excl.)
  • affected from 31910575a9de61e78065e93846e8e7a4894a18bf to b485eef3d97b7aae55ce669b6de555ec81f3d21c (excl.)
  • affected from 31910575a9de61e78065e93846e8e7a4894a18bf to ef3645606e4a635d5062a492f22b7f490852ee67 (excl.)
  • affected from 31910575a9de61e78065e93846e8e7a4894a18bf to ae05340ccaa9d347fe85415609e075545bec589f (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 2.6.24 is affected
  • unaffected from 0 to 2.6.24 (excl.)
  • unaffected from 5.10.253 to 5.10.* (incl.)
  • unaffected from 5.15.203 to 5.15.* (incl.)
  • unaffected from 6.1.168 to 6.1.* (incl.)
  • unaffected from 6.6.134 to 6.6.* (incl.)
  • unaffected from 6.12.81 to 6.12.* (incl.)
  • unaffected from 6.18.22 to 6.18.* (incl.)
  • unaffected from 6.19.12 to 6.19.* (incl.)
  • unaffected from 7.0 to * (incl.)

References