Kernel panic via unchecked durable-handle pointer
Published Jul 19, 2026 · Updated Jul 19, 2026
Null pointer dereference in Linux Kernel 7.0 through 7.0.10 allows remote attackers to prime a kernel panic via SMB2 durable handles. session_fd_check() clears fp->tcon during SMB2 SESSION_LOGOFF but leaves the file pointer in global_ft.idr, where proc_show_files() dereferences fp->tcon->id without a null check. Exposure also includes 7.1-rc1 through 7.1-rc4 and requires successful SMB2 SESSION_SETUP, durable handles enabled, and a privileged proc-file read during the timeout window; the panic interrupts the host.
Summary
What happened
Null pointer dereference in Linux Kernel 7.0 through 7.0.10 allows remote attackers to prime a kernel panic via SMB2 durable handles. session_fd_check() clears fp->tcon during SMB2 SESSION_LOGOFF but leaves the file pointer in global_ft.idr, where proc_show_files() dereferences fp->tcon->id without a null check. Exposure also includes 7.1-rc1 through 7.1-rc4 and requires successful SMB2 SESSION_SETUP, durable handles enabled, and a privileged proc-file read during the timeout window; the panic interrupts the host.
The record
- CVE
- CVE-2026-64140
- Published
- Jul 19, 2026
- Updated
- Jul 19, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-476, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 19, 2026CVE publishedPublication date reported by the CVE source.
- Jul 19, 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=7.0
- Affected versionversion=b38f99c1217ae04753340f0fdcd8f35bf56841dc <8eab081627b67216d1c8f638b68289b500dc9a6b
- Affected versionversion=b38f99c1217ae04753340f0fdcd8f35bf56841dc <904901561e61a2b559070b20c74a8c95491f30aa
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
Your stack
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Your stack
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