CVE-2026-31664

high

Description

In the Linux kernel, the following vulnerability has been resolved: xfrm: clear trailing padding in build_polexpire() build_expire() clears the trailing padding bytes of struct xfrm_user_expire after setting the hard field via memset_after(), but the analogous function build_polexpire() does not do this for struct xfrm_user_polexpire. The padding bytes after the __u8 hard field are left uninitialized from the heap allocation, and are then sent to userspace via netlink multicast to XFRMNLGRP_EXPIRE listeners, leaking kernel heap memory contents. Add the missing memset_after() call, matching build_expire().

References

https://git.kernel.org/stable/c/eda30846ea54f8ed218468e5480c8305ca645e37

https://git.kernel.org/stable/c/e1af65c669ebb1666c54576614c01a7f9ffcfff6

https://git.kernel.org/stable/c/c221ed63a2769a0af8bd849dfe25740048f34ef4

https://git.kernel.org/stable/c/b1dfd6b27df35ef4f87825aa5f607378d23ff0f2

https://git.kernel.org/stable/c/ac6985903db047eaff54db929e4bf6b06782788e

https://git.kernel.org/stable/c/71a98248c63c535eaa4d4c22f099b68d902006d0

Details

Source: Mitre, NVD

Published: 2026-04-24

Updated: 2026-04-24

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

Severity: Medium

CVSS v3

Base Score: 7.1

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Severity: High