CVE-2026-46195
In the Linux kernel, the following vulnerability has been resolved:
smb: client: validate dacloffset before building DACL pointers
parsesecdesc(), buildsecdesc(), and the chown path in
idmodetocifsacl() 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
U32MAX, wrap the derived DACL pointer below endof_acl, and then slip
past the later pointer-based bounds checks. buildsecdesc() and
idmodetocifsacl() 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.
Package Versions Affected
Automatically patch vulnerabilities without upgrading
CVSS Version



Related Resources
References
https://git.kernel.org/stable/c/3b1ddba19e77ee35241cd27f16dc3e8d14e08db7, https://git.kernel.org/stable/c/5de2665e913a10ad70aaeecf736b97276e83d995, https://git.kernel.org/stable/c/8bd07e417b6bda67e317920584e48cb6ee442a8a, https://git.kernel.org/stable/c/ba7f71b6161c0943dafc367565e5843d16b7d505, https://git.kernel.org/stable/c/c688f3ed73d31943334ad2139cb02ec49664322a, https://git.kernel.org/stable/c/f98b48151cc502ada59d9778f0112d21f2586ca3, https://git.kernel.org/stable/c/f9dc3be8f403c1216df73e57221f44b045e7ee0b, https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46195.json, https://access.redhat.com/errata/RHSA-2026:21556, https://access.redhat.com/errata/RHSA-2026:21706, https://access.redhat.com/errata/RHSA-2026:21745, https://access.redhat.com/security/cve/CVE-2026-46195, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46195.json, https://nvd.nist.gov/vuln/detail/CVE-2026-46195, https://bugzilla.redhat.com/show_bug.cgi?id=2482606, https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git