CVE-2026-46195 Details
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: validate dacloffset before building DACL pointers parse_sec_desc(), build_sec_desc(), and the chown path in id_mode_to_cifs_acl() all add the server-supplied dacloffset to pntsd before proving a DACL header fits inside the returned security descriptor. On 32-bit builds a malicious server can return dacloffset near U32_MAX, wrap the derived DACL pointer below end_of_acl, and then slip past the later pointer-based bounds checks. build_sec_desc() and id_mode_to_cifs_acl() can then dereference DACL fields from the wrapped pointer in the chmod/chown rewrite paths. Validate dacloffset numerically before building any DACL pointer and reuse the same helper at the three DACL entry points.
A vulnerability exists in the Linux kernel's SMB client implementation, specifically within the handling of Discretionary Access Control Lists (DACLs). The issue arises because the client does not properly validate the DACL offset received from the server before using it to build pointers to DACL data. This flaw can be exploited by a malicious server, particularly in 32-bit environments, by sending an offset that wraps around and bypasses normal bounds checks. As a result, the client may incorrectly process DACL information, potentially leading to unauthorized changes in file ownership or permissions.
Users can upgrade to the latest version of the Linux kernel where this vulnerability has been addressed. Instructions for upgrading the kernel can be found in the official Linux documentation.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-476 | NULL Pointer Dereference | [email protected] |
| CWE-787 | Out-of-bounds Write | redhat-SADP |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 5.12, < 6.6.140 >= 6.7, < 6.12.88 >= 6.13, < 6.18.30 >= 6.19, < 7.0.7 7.1 rc1 7.1 rc2 |
CPE
Remediation
| |
Change History
7 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 15, 2026 | CVE Modified | redhat-SADP |
| Jun 30, 2026 | CVE Modified | redhat-SADP |
| Jun 19, 2026 | CVE Modified | kernel.org |
| Jun 17, 2026 | CVE Modified | kernel.org |
| Jun 10, 2026 | Initial Analysis | [email protected] |
| May 30, 2026 | CVE Modified | kernel.org |
| May 28, 2026 | New CVE Received | kernel.org |