CVE-2026-64267
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.
Affected versions
Linux kernel versions
6.18
and later are affected. Fixed in
6.18.39,
7.1.4,
7.2-rc1
and their respective stable series.
References
3 totalFrequently asked questions
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What is CVE-2026-64267?
CVE-2026-64267 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.18 onward and has been patched in 6.18.39, 7.1.4 and 7.2-rc1. CVE-2026-64267 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-64267?
Yes. CVE-2026-64267 has been patched. Fixed versions include 6.18.39, 7.1.4 and 7.2-rc1. If you are running Linux kernel 6.18 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-64267 actively exploited?
No. CVE-2026-64267 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.