CVE-2026-31708

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-31708
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOB read in smb2_ioctl_query_info QUERY_INFO path smb2_ioctl_query_info() has two response-copy branches: PASSTHRU_FSCTL and the default QUERY_INFO path. The QUERY_INFO branch clamps qi.input_buffer_length to the server-reported OutputBufferLength and then copies qi.input_buffer_length bytes from qi_rsp->Buffer to userspace, but it never verifies that the flexible-array payload actually fits within rsp_iov[1].iov_len. A malicious server can return OutputBufferLength larger than the actual QUERY_INFO response, causing copy_to_user() to walk past the response buffer and expose adjacent kernel heap to userspace. Guard the QUERY_INFO copy with a bounds check on the actual Buffer payload. Use struct_size(qi_rsp, Buffer, qi.input_buffer_length) rather than an open-coded addition so the guard cannot overflow on 32-bit builds.

8.1 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 2.8 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/078fae8f50adebb903ccf2252b44391324571e78 Patch
https://git.kernel.org/stable/c/1dd757379997b71a328a4b591ffaf481acd0ead1
https://git.kernel.org/stable/c/85fd46ee26a11841c670449508025965f61ce131 Patch
https://git.kernel.org/stable/c/a34d456934fe42e4da5d2cc07787bf418bee99c6 Patch
https://git.kernel.org/stable/c/a58c5af19ff0d6f44f6e9fe31e33a2c92223f77e Patch
https://git.kernel.org/stable/c/ac2f14e4705d020f04e806efa0d49ab8dc2b145f Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
History

01 Jun 2026, 17:16

Type Values Removed Values Added
References
  • () https://git.kernel.org/stable/c/1dd757379997b71a328a4b591ffaf481acd0ead1 -

06 May 2026, 20:25

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/078fae8f50adebb903ccf2252b44391324571e78 - () https://git.kernel.org/stable/c/078fae8f50adebb903ccf2252b44391324571e78 - Patch
References () https://git.kernel.org/stable/c/85fd46ee26a11841c670449508025965f61ce131 - () https://git.kernel.org/stable/c/85fd46ee26a11841c670449508025965f61ce131 - Patch
References () https://git.kernel.org/stable/c/a34d456934fe42e4da5d2cc07787bf418bee99c6 - () https://git.kernel.org/stable/c/a34d456934fe42e4da5d2cc07787bf418bee99c6 - Patch
References () https://git.kernel.org/stable/c/a58c5af19ff0d6f44f6e9fe31e33a2c92223f77e - () https://git.kernel.org/stable/c/a58c5af19ff0d6f44f6e9fe31e33a2c92223f77e - Patch
References () https://git.kernel.org/stable/c/ac2f14e4705d020f04e806efa0d49ab8dc2b145f - () https://git.kernel.org/stable/c/ac2f14e4705d020f04e806efa0d49ab8dc2b145f - Patch
CWE CWE-125
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
First Time Linux
Linux linux Kernel

03 May 2026, 07:16

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 8.1

01 May 2026, 14:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-05-01 14:16

Updated : 2026-06-01 17:16

NVD link : CVE-2026-31708

Mitre link : CVE-2026-31708

CVE.ORG link : CVE-2026-31708

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-125

Out-of-bounds Read