Kernel memory corruption via wrapped DACL pointer
Published May 28, 2026 · Updated May 28, 2026
Out-of-bounds access in the Linux Kernel SMB client allows remote attackers to corrupt kernel memory through a crafted SMB DACL offset. parse_sec_desc(), build_sec_desc(), and id_mode_to_cifs_acl() add the server-supplied dacloffset to pntsd before proving that a DACL header fits, so 32-bit arithmetic can wrap the pointer below end_of_acl and evade later checks. Exploitation requires a 32-bit build and client processing of a malicious server security descriptor; chmod or chown rewrite paths then dereference fields through the wrapped pointer.
Summary
What happened
Out-of-bounds access in the Linux Kernel SMB client allows remote attackers to corrupt kernel memory through a crafted SMB DACL offset. parse_sec_desc(), build_sec_desc(), and id_mode_to_cifs_acl() add the server-supplied dacloffset to pntsd before proving that a DACL header fits, so 32-bit arithmetic can wrap the pointer below end_of_acl and evade later checks. Exploitation requires a 32-bit build and client processing of a malicious server security descriptor; chmod or chown rewrite paths then dereference fields through the wrapped pointer.
The record
- CVE
- CVE-2026-46195
- Published
- May 28, 2026
- Updated
- May 28, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-476, CWE-787, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 28, 2026CVE publishedPublication date reported by the CVE source.
- May 28, 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=5.12
- Affected versionversion=bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 <3b1ddba19e77ee35241cd27f16dc3e8d14e08db7
- Affected versionversion=bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 <8bd07e417b6bda67e317920584e48cb6ee442a8a
- Affected versionversion=bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 <ba7f71b6161c0943dafc367565e5843d16b7d505
- Affected versionversion=bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 <c688f3ed73d31943334ad2139cb02ec49664322a
- Affected versionversion=bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 <f98b48151cc502ada59d9778f0112d21f2586ca3
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Published CVSS scores
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Attacks
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