CVE-2026-43112
fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath
- State
- Published
- Severity
- 8.8 High
- Published
- May 6, 2026
- Updated
- Oct 19, 2026
- Reserved
- May 1, 2026
Description
In the Linux kernel, the following vulnerability has been resolved:
fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath
When cifs_sanitize_prepath is called with an empty string or a string containing only delimiters (e.g., "/"), the current logic attempts to check *(cursor2 - 1) before cursor2 has advanced. This results in an out-of-bounds read.
This patch adds an early exit check after stripping prepended delimiters. If no path content remains, the function returns NULL.
The bug was identified via manual audit and verified using a standalone test case compiled with AddressSanitizer, which triggered a SEGV on affected inputs.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 8.8 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H | Linux |
| 3.1 | 8.1 High | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H | redhat-SADP |
Weaknesses
- CWE-125 Out-of-bounds Read
Affected Products
| Product | Versions |
|---|---|
LinuxLinux |
|
LinuxLinux |
|
References
- https://git.kernel.org/stable/c/a2ba20c17de8eb028f96b1d85f119d3d25655bd9
- https://git.kernel.org/stable/c/fbced33599653471b4581dfe1abc7b467031f126
- https://git.kernel.org/stable/c/5d4fe469fe7dbff7d874c196bb680a82f2625d95
- https://git.kernel.org/stable/c/2d29214448ec0f4e7e18bb1c14dd4a6c07f1c439
- https://git.kernel.org/stable/c/86f9c23e0814cfdffda9eedf0c591c51ba209010
- https://git.kernel.org/stable/c/49b1ce6d7cfb6c5a49f68bf5ccfcfb6ba14e63c3
- https://git.kernel.org/stable/c/78ec5bf2f589ec7fd8f169394bfeca541b077317
- https://access.redhat.com/security/cve/CVE-2026-43112vdb-entry
- RHBZ#2467015issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43112.json
- https://access.redhat.com/errata/RHSA-2026:59831vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:65839vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:62409vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:62549vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:60019vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:65851vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:57402vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:57543vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:57457vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:40764vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:52764vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:34911vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:59662vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:56573vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:53990vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:36018vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:62642vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:36366vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:62637vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:53989vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:52649vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:62558vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:62638vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:62639vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:62641vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:62640vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:36365vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:59663vendor-advisory
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
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