CVE-2026-46182 pseries/papr-hvpipe: Prevent kernel stack memory leak to userspace

Medium 5.5 Published Updated

An attacker can read uninitialized kernel stack memory via the papr-hvpipe driver due to missing initialization of padding bytes.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
Available

What is CVE-2026-46182?

CVE-2026-46182 is a medium-severity vulnerability in Linux kernel, published on 28 May 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:

pseries/papr-hvpipe: Prevent kernel stack memory leak to userspace

The hdr variable is allocated on the stack and only hdr.version and hdr.flags are initialized explicitly. Because the struct papr_hvpipe_hdr contains reserved padding bytes (reserved[3] and reserved2[40]), these could leak the uninitialized bytes to userspace after copy_to_user().

This patch fixes that by initializing the whole struct to 0.

Weakness: CWE-401

Which versions are affected by CVE-2026-46182?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-46182?

Apply the vendor's patch.

Is CVE-2026-46182 being exploited?

There is no known exploitation of CVE-2026-46182 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2026-46182, DEBIAN-CVE-2026-46182, GHSA-2vh6-g7pq-9fgv, UBUNTU-CVE-2026-46182.

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