CVE-2026-31671 xfrm_user: fix info leak in build_report()

What is CVE-2026-31671?

CVE-2026-31671 is a medium-severity vulnerability in Linux kernel, published on 24 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

xfrm_user: fix info leak in build_report()

struct xfrm_user_report is a __u8 proto field followed by a struct xfrm_selector which means there is three "empty" bytes of padding, but the padding is never zeroed before copying to userspace. Fix that up by zeroing the structure before setting individual member variables.

Weakness: CWE-401

Which versions are affected by CVE-2026-31671?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-31671?

Apply the vendor's patch.

Is CVE-2026-31671 being exploited?

There is no known exploitation of CVE-2026-31671 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-83765, BELL-CVE-2026-31671, DEBIAN-CVE-2026-31671, GHSA-rv96-q2g6-r95w, ROOT-OS-DEBIAN-11-CVE-2026-31671, ROOT-OS-DEBIAN-12-CVE-2026-31671 and 3 more.