CVE-2026-64519 NFSD: Fix infinite loop in layout state revocation
An attacker can cause a denial of service in the Linux kernel's NFSD by triggering an infinite loop during layout state revocation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-64519?
CVE-2026-64519 is a denial of service vulnerability in Linux, published on 25 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Fix infinite loop in layout state revocation
find_one_sb_stid() skips stids whose sc_status is non-zero, but the SC_TYPE_LAYOUT case in nfsd4_revoke_states() never sets sc_status before calling nfsd4_close_layout(). The retry loop therefore finds the same layout stid on every iteration, hanging the revoker indefinitely.
Which versions are affected by CVE-2026-64519?
How do I fix CVE-2026-64519?
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-2026-64519 being exploited?
There is no known exploitation of CVE-2026-64519 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-64519, DEBIAN-CVE-2026-64519, GHSA-gv69-m9qg-32px, ROOT-OS-UBUNTU-2204-CVE-2026-64519, UBUNTU-CVE-2026-64519.