Remote timestamp corruption via NFSv2 useconds overflow
Published Sep 11, 2026 · Updated Sep 11, 2026
Integer overflow in the Linux kernel's NFSv2 server allows remote authenticated users to write incorrect file timestamps via SETATTR or CREATE. On ILP32 builds, svcxdr_decode_sattr multiplies an unchecked 32-bit microseconds value by 1,000, allowing the product to wrap into an apparently valid tv_nsec value before later validation. Exploitation requires NFSv2 access permitting the requested operation; the bounded impact is incorrect file timestamp metadata.
Summary
What happened
Integer overflow in the Linux kernel's NFSv2 server allows remote authenticated users to write incorrect file timestamps via SETATTR or CREATE. On ILP32 builds, svcxdr_decode_sattr multiplies an unchecked 32-bit microseconds value by 1,000, allowing the product to wrap into an apparently valid tv_nsec value before later validation. Exploitation requires NFSv2 access permitting the requested operation; the bounded impact is incorrect file timestamp metadata.
The record
- CVE
- CVE-2026-89665
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1070.006
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 11, 2026CVE publishedPublication date reported by the CVE source.
- Sep 11, 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?
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- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1195483965a5f63d2dde18054ec7e50a23b9071c
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <26709c8ffe73772eb69e68d553ac71d91228dccc
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a937dd1aa2d92291fe0a1860d17e90d8f206cd22
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ad02d095439f89cbd6629420c7e3ba476457b83b
- Affected versionversion=2.6.12
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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