CVE-2026-46195

high

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.

References

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46195.json

https://git.kernel.org/stable/c/f9dc3be8f403c1216df73e57221f44b045e7ee0b

https://git.kernel.org/stable/c/f98b48151cc502ada59d9778f0112d21f2586ca3

https://git.kernel.org/stable/c/c688f3ed73d31943334ad2139cb02ec49664322a

https://git.kernel.org/stable/c/ba7f71b6161c0943dafc367565e5843d16b7d505

https://git.kernel.org/stable/c/8bd07e417b6bda67e317920584e48cb6ee442a8a

https://git.kernel.org/stable/c/5de2665e913a10ad70aaeecf736b97276e83d995

https://git.kernel.org/stable/c/3b1ddba19e77ee35241cd27f16dc3e8d14e08db7

https://bugzilla.redhat.com/show_bug.cgi?id=2482606

https://access.redhat.com/security/cve/CVE-2026-46195

https://access.redhat.com/errata/RHSA-2026:21745

https://access.redhat.com/errata/RHSA-2026:21706

https://access.redhat.com/errata/RHSA-2026:21556

Details

Source: Mitre, NVD

Published: 2026-05-28

Updated: 2026-06-30

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00018