CVE-2026-64267

Medium

Description

In the Linux kernel, the following vulnerability has been resolved: fuse: avoid 32-bit prune notification count wrap FUSE_NOTIFY_PRUNE validates the nodeid payload length with: size - sizeof(outarg) != outarg.count * sizeof(u64) On 32-bit kernels, size_t is also 32 bits, so the daemon-controlled count multiplication can wrap. A prune notification with count 0x20000000 and no nodeid payload passes the check, enters the copy loop, and asks the device copy path to read nodeids that are not present in the userspace write buffer. In QEMU this reaches the fuse_copy_fill() BUG_ON(!err) path. Validate the payload length with array_size() instead. That accepts exactly the same valid messages, but avoids wrapping arithmetic before the copy loop consumes the count.

SeverityMedium
CVSS5.5
Exploit probability—
ProductLinux Kernel
PublishedJul 25, 2026
First seenJul 25, 2026

How to fix

Update
  • linux linux_kernel6.18.39, 7.1.4 or later

Affected products

ProductAffected versionsFixed in
linux linux_kernel6.18 ≤ v < 6.18.39, 6.19 ≤ v < 7.1.46.18.39, 7.1.4

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.