CVE-2026-64217 netfs: Fix overrun check in netfs_extract_user_iter()
A flaw in the Linux kernel netfs subsystem allows memory corruption via an overrun check failure, potentially enabling code execution or privilege escalation.
- 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-2026-64217?
CVE-2026-64217 is a high-severity memory corruption vulnerability in Linux kernel, published on 24 Jul 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:
netfs: Fix overrun check in netfs_extract_user_iter()
Fix netfs_extract_user_iter() so that if iov_iter_extract_pages() overfills pages[], then those pages don't get included in the iterator constructed at the end of the function. If there was an overfill, memory corruption has already happened.
Weakness: CWE-787
Which versions are affected by CVE-2026-64217?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-64217?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-64217 being exploited?
There is no known exploitation of CVE-2026-64217 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-64217, DEBIAN-CVE-2026-64217, GHSA-782q-hrc8-fp6w, ROOT-OS-UBUNTU-2204-CVE-2026-64217, UBUNTU-CVE-2026-64217.