Filesystem hang via unchecked io-uring negotiation
Published Sep 17, 2026 · Updated Sep 17, 2026
Deadlock in FUSE in Linux 6.14 allows local users to hang filesystem I/O via io-uring commands on an unnegotiated connection. fuse_uring_cmd() accepts IORING_OP_URING_CMD without the server's FUSE_OVER_IO_URING initialization flag, bypassing readiness synchronization and allowing background and queue locks to deadlock. Triggering requires access to the local FUSE server command path and concurrent I/O; the disclosed consequence is a hang, not data disclosure or code execution.
Summary
What happened
Deadlock in FUSE in Linux 6.14 allows local users to hang filesystem I/O via io-uring commands on an unnegotiated connection. fuse_uring_cmd() accepts IORING_OP_URING_CMD without the server's FUSE_OVER_IO_URING initialization flag, bypassing readiness synchronization and allowing background and queue locks to deadlock. Triggering requires access to the local FUSE server command path and concurrent I/O; the disclosed consequence is a hang, not data disclosure or code execution.
The record
- CVE
- CVE-2026-90095
- Published
- Sep 17, 2026
- Updated
- Sep 17, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 17, 2026CVE publishedPublication date reported by the CVE source.
- Sep 17, 2026Record updatedLatest update available in the CVE record.
Exploitability
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Is a vulnerable build present?
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- Affected versionversion=3393ff964e0fa5def66570c54a4612bf9df06b76 <1f59015e958174e89be58cc8db16d70a60d17255
- Affected versionversion=3393ff964e0fa5def66570c54a4612bf9df06b76 <8f9a725d89711ad027f6b7183586ef91528f106d
- Affected versionversion=6.14
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
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