Kernel heap disclosure via uninitialized response padding
Published Sep 16, 2026 · Updated Sep 16, 2026
Information disclosure in Linux ksmbd allows remote attackers to read up to seven bytes of kernel heap data through an SMB pipe response. The smb2_read_pipe() function allocates only the RPC payload length, but compound-response handling extends its final iovec to an eight-byte boundary and transmits the uninitialized tail. The flaw is reachable only when ksmbd is configured and serving SMB requests, and each affected response exposes no more than seven heap bytes.
Summary
What happened
Information disclosure in Linux ksmbd allows remote attackers to read up to seven bytes of kernel heap data through an SMB pipe response. The smb2_read_pipe() function allocates only the RPC payload length, but compound-response handling extends its final iovec to an eight-byte boundary and transmits the uninitialized tail. The flaw is reachable only when ksmbd is configured and serving SMB requests, and each affected response exposes no more than seven heap bytes.
The record
- CVE
- CVE-2026-89794
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1005
- Attack vector
- network
- 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=5.15.145 <5.16
- Affected versionversion=6.1.71 <6.2
- Affected versionversion=6.6
- Affected versionversion=9f297df20d93411c0b4ddad7f88ba04a7cd36e77
- Affected versionversion=e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d <73f860489e3be2245598d1819226304fc5b87291
- Affected versionversion=e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d <be15b8da4a82cf1e1f9880b2661b90770606eec1
- Affected versionversion=e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d <d83a9de7cecd401c3d3e00ed6371194dcd7313e4
- Affected versionversion=e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d <f188a400dd5285fec5a84548fe8dca49eee01155
- Affected versionversion=f2283680a80571ca82d710bc6ecd8f8beac67d63
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
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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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