Memory disclosure and crash via unchecked SMB offsets
Published Oct 4, 2025 · Updated Oct 4, 2025
Out-of-bounds access in Linux 4.16 through 6.16.8 and 6.17-rc1 through 6.17-rc6 allows remote attackers to disclose kernel memory. The recv_done path trusts server-supplied data_offset, data_length, and remaining_data_length, letting copy_to_iter read beyond its receive buffer or dereference a NULL reassembly entry. An affected client must mount an attacker-controlled SMB Direct share; successful exploitation returns unintended kernel data or crashes the host.
Summary
What happened
Out-of-bounds access in Linux 4.16 through 6.16.8 and 6.17-rc1 through 6.17-rc6 allows remote attackers to disclose kernel memory. The recv_done path trusts server-supplied data_offset, data_length, and remaining_data_length, letting copy_to_iter read beyond its receive buffer or dereference a NULL reassembly entry. An affected client must mount an attacker-controlled SMB Direct share; successful exploitation returns unintended kernel data or crashes the host.
The record
- CVE
- CVE-2025-39933
- Published
- Oct 4, 2025
- Updated
- Oct 4, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 4, 2025CVE publishedPublication date reported by the CVE source.
- Oct 4, 2025Record 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=4.16
- Affected versionversion=f198186aa9bbd60fae7a2061f4feec614d880299 <581fb78e0388b78911b0c920e4073737090c8b5f
- Affected versionversion=f198186aa9bbd60fae7a2061f4feec614d880299 <f57e53ea252363234f86674db475839e5b87102e
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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