Vulnerability Details CVE-2026-64264
In the Linux kernel, the following vulnerability has been resolved:
fuse-uring: fix EFAULT clobber in fuse_uring_commit
copy_from_user() returns the number of bytes not copied as an unsigned
residual on failure (1..sizeof(struct fuse_out_header)). fuse_uring_commit
stores that residual in ssize_t err, sets req->out.h.error to -EFAULT,
then jumps to out: with err still holding the positive residual.
err = copy_from_user(&req->out.h, &ent->headers->in_out,
sizeof(req->out.h));
if (err) {
req->out.h.error = -EFAULT;
goto out; /* err is the positive residual */
}
...
out:
fuse_uring_req_end(ent, req, err);
fuse_uring_req_end() then runs
if (error)
req->out.h.error = error;
which overwrites the just-assigned -EFAULT with the positive residual.
FUSE callers such as fuse_simple_request() test err < 0 to detect
failure, so the positive value is interpreted as success and the
caller proceeds with an uninitialised or partial req->out.args.
Fix by assigning err = -EFAULT in the failure branch before jumping
to out, so fuse_uring_req_end() receives a negative errno and sets
req->out.h.error to -EFAULT.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 9.8%
CVSS Severity
CVSS v3 Score 5.5
Products affected by CVE-2026-64264
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cpe:2.3:o:linux:linux_kernel:6.19
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cpe:2.3:o:linux:linux_kernel:6.19.1
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cpe:2.3:o:linux:linux_kernel:6.19.10
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cpe:2.3:o:linux:linux_kernel:6.19.11
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cpe:2.3:o:linux:linux_kernel:6.19.12
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cpe:2.3:o:linux:linux_kernel:6.19.13
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cpe:2.3:o:linux:linux_kernel:6.19.14
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cpe:2.3:o:linux:linux_kernel:6.19.3
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cpe:2.3:o:linux:linux_kernel:6.19.4
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cpe:2.3:o:linux:linux_kernel:6.19.6
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cpe:2.3:o:linux:linux_kernel:6.19.7
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cpe:2.3:o:linux:linux_kernel:6.19.8
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cpe:2.3:o:linux:linux_kernel:6.19.9
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cpe:2.3:o:linux:linux_kernel:7.0
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cpe:2.3:o:linux:linux_kernel:7.0.1
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cpe:2.3:o:linux:linux_kernel:7.0.10
-
cpe:2.3:o:linux:linux_kernel:7.0.11
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cpe:2.3:o:linux:linux_kernel:7.0.12
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cpe:2.3:o:linux:linux_kernel:7.0.13
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cpe:2.3:o:linux:linux_kernel:7.0.14
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cpe:2.3:o:linux:linux_kernel:7.0.2
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cpe:2.3:o:linux:linux_kernel:7.0.3
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cpe:2.3:o:linux:linux_kernel:7.0.4
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cpe:2.3:o:linux:linux_kernel:7.0.5
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cpe:2.3:o:linux:linux_kernel:7.0.6
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cpe:2.3:o:linux:linux_kernel:7.0.7
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cpe:2.3:o:linux:linux_kernel:7.0.8
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cpe:2.3:o:linux:linux_kernel:7.0.9
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cpe:2.3:o:linux:linux_kernel:7.1
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cpe:2.3:o:linux:linux_kernel:7.1.1
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cpe:2.3:o:linux:linux_kernel:7.1.2