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.
Fix
Patch, vendor advisory and mitigation references on NVD 5
- https://git.kernel.org/stable/c/3b1ddba19e77ee35241cd27f16dc3e8d14e08db7 Patch
- https://git.kernel.org/stable/c/8bd07e417b6bda67e317920584e48cb6ee442a8a Patch
- https://git.kernel.org/stable/c/ba7f71b6161c0943dafc367565e5843d16b7d505 Patch
- https://git.kernel.org/stable/c/c688f3ed73d31943334ad2139cb02ec49664322a Patch
- https://git.kernel.org/stable/c/f98b48151cc502ada59d9778f0112d21f2586ca3 Patch
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 2
- CwesCWE-476, CWE-787 → CWE-476, CWE-190, CWE-787NVD modified 2026-10-19 20:18
- First seenCVSS 9.8 · linuxNVD modified 2026-10-15 02:19
Affected (CPE criteria) 3
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
References 14
- https://git.kernel.org/stable/c/3b1ddba19e77ee35241cd27f16dc3e8d14e08db7 Patch
- https://git.kernel.org/stable/c/5de2665e913a10ad70aaeecf736b97276e83d995
- https://git.kernel.org/stable/c/8bd07e417b6bda67e317920584e48cb6ee442a8a Patch
- https://git.kernel.org/stable/c/ba7f71b6161c0943dafc367565e5843d16b7d505 Patch
- https://git.kernel.org/stable/c/c688f3ed73d31943334ad2139cb02ec49664322a Patch
- https://git.kernel.org/stable/c/f98b48151cc502ada59d9778f0112d21f2586ca3 Patch
- https://git.kernel.org/stable/c/f9dc3be8f403c1216df73e57221f44b045e7ee0b
- 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://bugzilla.redhat.com/show_bug.cgi?id=2482606
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46195.json