CVE-2026-31643 rxrpc: Fix key parsing memleak

Medium 5.5 Published Updated

A memory leak in the Linux kernel's rxrpc key parsing allows attackers to exhaust system memory, potentially causing a denial of service.

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-2026-31643?

CVE-2026-31643 is a medium-severity denial of service 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:

rxrpc: Fix key parsing memleak

In rxrpc_preparse_xdr_yfs_rxgk(), the memory attached to token->rxgk can be leaked in a few error paths after it's allocated.

Fix this by freeing it in the "reject_token:" case.

Weakness: CWE-401

Which versions are affected by CVE-2026-31643?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-31643?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-31643 being exploited?

There is no known exploitation of CVE-2026-31643 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2026-31643, DEBIAN-CVE-2026-31643, GHSA-cmpj-rg49-j7hv, UBUNTU-CVE-2026-31643.

Is CVE-2026-31643 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free