Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
Linux Linux — fuse: avoid 32-bit prune notification count wrap
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U N N H 5.5 .0015 5.0 —
AFFECTED
Product Versions Fixed
Linux 3f29d59e92a96d843c2ff10ebfed92ac26878658 – —
Linux 6.18 – 6.18.39
TIMELINE
Jul 19 Reserved by Linux
Jul 25 Published (CNA: Linux)
Aug 17 ENRICHED — CVE-2026-64267 (Linux). Received CVSS 5.5 and CPE data from NVD.
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.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
| July 19, 2026 | Reserved | Reserved by Linux |
| July 25, 2026 | Published | Published (CNA: Linux) |
| August 17, 2026 | ENRICHED | ENRICHED — CVE-2026-64267 (Linux). Received CVSS 5.5 and CPE data from NVD. |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| Linux | Linux | — | 3f29d59e92a96d843c2ff10ebfed92ac26878658 | — |
| Linux | Linux | — | 6.18 | 6.18.39 |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-64267 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.