Authenticated kernel memory corruption via lease-reference race
Published Aug 15, 2026 · Updated Aug 15, 2026
Use-after-free in Linux kernel ksmbd allows remote authenticated users to crash or corrupt the SMB server through concurrent lease operations. same_client_has_lease() returns an oplock_info pointer after releasing ci->m_lock without retaining a reference, and smb_grant_oplock() later dereferences it after a concurrent close can free it. A valid SMB2 session, tree connection, share permission, and SMB3 leasing are required; exploitation can panic the host or corrupt kernel memory.
Summary
What happened
Use-after-free in Linux kernel ksmbd allows remote authenticated users to crash or corrupt the SMB server through concurrent lease operations. same_client_has_lease() returns an oplock_info pointer after releasing ci->m_lock without retaining a reference, and smb_grant_oplock() later dereferences it after a concurrent close can free it. A valid SMB2 session, tree connection, share permission, and SMB3 leasing are required; exploitation can panic the host or corrupt kernel memory.
The record
- CVE
- CVE-2026-72492
- Published
- Aug 15, 2026
- Updated
- Aug 15, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 15, 2026CVE publishedPublication date reported by the CVE source.
- Aug 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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- Affected versionversion=5.15
- Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <09634cd055d9bd8dd167995ea52bcd8028dd5dac
- Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <0ff82a9cf9312678d8bc4edeef0b6e82659ac12a
- Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <35d3d6ff2bc1e7aaecb15d5377ebbd6227acae0d
- Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <65b655f65c3ca1ab5d598d3832bb0ff531725858
- Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <79c7c59bb519db6f5a2a151965e825ec725614cc
- Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <7c3264d273d524aa6adcce23c01087271f13586f
- Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <aaa3bb2bbf2ccbfea9e4e0b9dabf3afc60b50cd0
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What is affected?
Published CVSS scores
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Attacks
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