smb: client: validate dacloffset before building DACL pointers
Summary
| CVE | CVE-2026-46195 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-28 10:16:35 UTC |
| Updated | 2026-05-30 11:17:25 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 9.8 CRITICAL from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.000180000 probability, percentile 0.051640000 (date 2026-05-29)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 ba7f71b6161c0943dafc367565e5843d16b7d505 git | Not specified |
| CNA | Linux | Linux | affected bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 3b1ddba19e77ee35241cd27f16dc3e8d14e08db7 git | Not specified |
| CNA | Linux | Linux | affected bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 c688f3ed73d31943334ad2139cb02ec49664322a git | Not specified |
| CNA | Linux | Linux | affected bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 8bd07e417b6bda67e317920584e48cb6ee442a8a git | Not specified |
| CNA | Linux | Linux | affected bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 f98b48151cc502ada59d9778f0112d21f2586ca3 git | Not specified |
| CNA | Linux | Linux | affected 5.12 | Not specified |
| CNA | Linux | Linux | unaffected 5.12 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.140 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.88 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.30 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.7 7.0.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1-rc3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/c688f3ed73d31943334ad2139cb02ec49664322a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/8bd07e417b6bda67e317920584e48cb6ee442a8a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/3b1ddba19e77ee35241cd27f16dc3e8d14e08db7 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/f98b48151cc502ada59d9778f0112d21f2586ca3 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/ba7f71b6161c0943dafc367565e5843d16b7d505 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.