Uninitialized output use via clobbered EFAULT result
Published Jul 25, 2026 · Updated Jul 25, 2026
Improper error handling in Linux Kernel 6.14 allows attackers to trigger use of uninitialized or partial FUSE output arguments. In fuse_uring_commit, a positive copy_from_user residual survives the failure branch, and fuse_uring_req_end overwrites the stored -EFAULT with that value, which callers interpret as success. Reachability requires the affected FUSE io_uring path; the upstream record does not identify the required privileges or whether the resulting use causes disclosure, corruption, a crash, or another consequence.
Summary
What happened
Improper error handling in Linux Kernel 6.14 allows attackers to trigger use of uninitialized or partial FUSE output arguments. In fuse_uring_commit, a positive copy_from_user residual survives the failure branch, and fuse_uring_req_end overwrites the stored -EFAULT with that value, which callers interpret as success. Reachability requires the affected FUSE io_uring path; the upstream record does not identify the required privileges or whether the resulting use causes disclosure, corruption, a crash, or another consequence.
The record
- CVE
- CVE-2026-64264
- Published
- Jul 25, 2026
- Updated
- Jul 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Jul 25, 2026CVE publishedPublication date reported by the CVE source.
- Jul 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.14
- Affected versionversion=c090c8abae4b6b77a1bee116aa6c385456ebef96 <0483fffdeeb363f320e6bf5fc0f0306007507306
- Affected versionversion=c090c8abae4b6b77a1bee116aa6c385456ebef96 <3a0a8bc51a13951c5141262bf770eeea3e0b6228
- Affected versionversion=c090c8abae4b6b77a1bee116aa6c385456ebef96 <fe604c08d874648a69187f6380e5c7858627dc04
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
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Public exploit references
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Technologies
Your stack
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Your stack
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