Use-after-free via unpinned NFSv4 client
Published Sep 16, 2026 · Updated Sep 16, 2026
A use-after-free in Linux NFSD allows attackers to dereference a freed NFSv4 client during concurrent blocked-lock reaping and expiry. A bare lock owner retains only a raw client pointer, while the laundromat drops its owner reference before nfs4_put_stateowner takes cl_lock. Exploitation requires the reaping path to race client expiration; the resulting memory-safety consequence beyond the freed lock dereference is not published.
Summary
What happened
A use-after-free in Linux NFSD allows attackers to dereference a freed NFSv4 client during concurrent blocked-lock reaping and expiry. A bare lock owner retains only a raw client pointer, while the laundromat drops its owner reference before nfs4_put_stateowner takes cl_lock. Exploitation requires the reaping path to race client expiration; the resulting memory-safety consequence beyond the freed lock dereference is not published.
The record
- CVE
- CVE-2026-90036
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 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=4.9
- Affected versionversion=7919d0a27f1e7cb324e023776aa1cbff00f1ee7b <6fedb2eaff77554ca7a0deffd2e8bc0d6e8b38b0
- Affected versionversion=7919d0a27f1e7cb324e023776aa1cbff00f1ee7b <9026932ac8be4d0ae01db47f23619a98cc57b671
- Affected versionversion=7919d0a27f1e7cb324e023776aa1cbff00f1ee7b <cd489b03587378645fe0d20142a33f1ed60bac98
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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