Authenticated kernel memory corruption via negative SMB offset
Published Dec 27, 2024 · Updated Aug 5, 2026
Out-of-bounds write in Linux 5.15 through 6.13-rc1 allows remote authenticated users to corrupt kernel memory via an SMB2 WRITE request. ksmbd_vfs_stream_write accepts the client-controlled signed offset without rejecting negative values, so it writes the supplied payload before the allocated stream buffer. Reachability requires streams_xattr in ksmbd.conf, an authenticated SMB session, a writable tree connection, and an open handle with write access; the resulting primitive supports kernel memory disclosure, arbitrary writes, control-flow hijacking, and host panic.
Summary
What happened
Out-of-bounds write in Linux 5.15 through 6.13-rc1 allows remote authenticated users to corrupt kernel memory via an SMB2 WRITE request. ksmbd_vfs_stream_write accepts the client-controlled signed offset without rejecting negative values, so it writes the supplied payload before the allocated stream buffer. Reachability requires streams_xattr in ksmbd.conf, an authenticated SMB session, a writable tree connection, and an open handle with write access; the resulting primitive supports kernel memory disclosure, arbitrary writes, control-flow hijacking, and host panic.
The record
- CVE
- CVE-2024-56626
- Published
- Dec 27, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1210
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 27, 2024CVE publishedPublication date reported by the CVE source.
- Aug 5, 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=0626e6641f6b467447c81dd7678a69c66f7746cf <164d3597d26d9acff5d5b8bc3208bdcca942dd6a
- Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <1aea5c9470be2c7129704fb1b9562b1e3e0576f8
- Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <313dab082289e460391c82d855430ec8a28ddf81
- Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <8cd7490fc0f268883e86e840cda5311257af69ca
- Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <c5797f195c67132d061d29c57a7c6d30530686f0
- Affected versionversion=5.15
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
Public exploit references
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Technologies
Your stack
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Your stack
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