CVE-2026-46195
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.68%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.68% probability · 50th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-476, CWE-787
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/3b1ddba19e77ee35241cd27f16dc3e8d14e08db7Patch
- https://git.kernel.org/stable/c/5de2665e913a10ad70aaeecf736b97276e83d995
- https://git.kernel.org/stable/c/8bd07e417b6bda67e317920584e48cb6ee442a8aPatch
- https://git.kernel.org/stable/c/ba7f71b6161c0943dafc367565e5843d16b7d505Patch
- https://git.kernel.org/stable/c/c688f3ed73d31943334ad2139cb02ec49664322aPatch
- https://git.kernel.org/stable/c/f98b48151cc502ada59d9778f0112d21f2586ca3Patch
- 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://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46195.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.