CVE-2026-43089: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: xfrm_user: fix info leak in build_mapping() struct xfrm_usersa_id has a one-byte padding hole after the proto field, which ends up never getting set to zero before copying out to userspace. Fix that up by zeroing out the whole structure before setting individual variables.

Affected products

• Linux Linux Kernel: from 2.6.29.1, before 6.6.136 (fixed in 6.6.136); from 6.7, before 6.12.83 (fixed in 6.12.83); from 6.13, before 6.18.24 (fixed in 6.18.24); from 6.19, before 6.19.14 (fixed in 6.19.14); version 7.0 only

Published 2026-05-06. Last modified 2026-09-08.