CVE Catalog

CVE-2026-64267

MediumCVSS 5.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.15%

5th percentile - higher than 5% of all known CVEs

Summary

In the FUSE filesystem in the Linux kernel, there is a vulnerability due to 32-bit multiplication wrap in the prune notification payload length validation. The daemon-controlled multiplication count * sizeof(u64) can wrap, bypassing the check and leading to out-of-bounds read.

Risk Assessment

An attacker can exploit this to trigger a BUG_ON in the copy path, causing a system crash (kernel panic) or potentially other undesirable behavior.

Recommendation

Apply the Linux kernel patch that uses array_size() to validate the payload length, preventing arithmetic wrap.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS