CVE-2026-46195
CRITICALDescription
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.
CVSS v3 vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected routers (0)
No routers currently mapped to this CVE in our database.