CVE-2026-64208 crypto/krb5, rxrpc: Fix lack of pre-decrypt/pre-verify length checks
Missing length checks in Linux kernel crypto and rxrpc modules allow attackers to cause denial of service via malformed packets.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-64208?
CVE-2026-64208 is a high-severity denial of service vulnerability in Linux kernel, published on 24 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
crypto/krb5, rxrpc: Fix lack of pre-decrypt/pre-verify length checks
Change the krb5 crypto library to provide facilities to precheck the length of the message about to be decrypted or verified.
Fix AF_RXRPC to make use of this to validate DATA packets secured with RxGK.
Which versions are affected by CVE-2026-64208?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-64208?
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-2026-64208 being exploited?
There is no known exploitation of CVE-2026-64208 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-64208, DEBIAN-CVE-2026-64208, GHSA-h9mq-35p6-m5v2, ROOT-OS-UBUNTU-2204-CVE-2026-64208, UBUNTU-CVE-2026-64208.