cbcvebase.
CVE-2026-31708
published 2026-05-01

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()…

PriorityP341high8.1CVSS 3.1
AVNACLPRNUIRSUCHINAH
EPSS
0.31%
23.0th percentile
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.

Affected

40 ranges· showing 25
VendorProductVersion rangeFixed in
linuxlinux
linuxlinux>= f5778c398713692a16150ae96e5c8270bab8399f < e66bdc0704977ecee667a81d38255b579c2353d0e66bdc0704977ecee667a81d38255b579c2353d0
linuxlinux>= f5778c398713692a16150ae96e5c8270bab8399f < 9e203dbb5402897c43130fb171a2617008a91f459e203dbb5402897c43130fb171a2617008a91f45
linuxlinux>= f5778c398713692a16150ae96e5c8270bab8399f < 1dd757379997b71a328a4b591ffaf481acd0ead11dd757379997b71a328a4b591ffaf481acd0ead1
linuxlinux>= f5778c398713692a16150ae96e5c8270bab8399f < a34d456934fe42e4da5d2cc07787bf418bee99c6a34d456934fe42e4da5d2cc07787bf418bee99c6
linuxlinux>= f5778c398713692a16150ae96e5c8270bab8399f < ac2f14e4705d020f04e806efa0d49ab8dc2b145fac2f14e4705d020f04e806efa0d49ab8dc2b145f
linuxlinux>= f5778c398713692a16150ae96e5c8270bab8399f < 078fae8f50adebb903ccf2252b44391324571e78078fae8f50adebb903ccf2252b44391324571e78
linuxlinux>= f5778c398713692a16150ae96e5c8270bab8399f < 85fd46ee26a11841c670449508025965f61ce13185fd46ee26a11841c670449508025965f61ce131
linuxlinux>= f5778c398713692a16150ae96e5c8270bab8399f < a58c5af19ff0d6f44f6e9fe31e33a2c92223f77ea58c5af19ff0d6f44f6e9fe31e33a2c92223f77e
linuxlinux_kernel
linuxlinux_kernel>= 5.1 < 6.6.1366.6.136
linuxlinux_kernel>= 6.13 < 6.18.256.18.25
linuxlinux_kernel>= 6.19 < 7.0.27.0.2
linuxlinux_kernel>= 6.7 < 6.12.846.12.84
ubuntulinux
ubuntulinux-aws
ubuntulinux-azure
ubuntulinux-azure-6.8
ubuntulinux-azure-fde
ubuntulinux-azure-fde-6.8
ubuntulinux-azure-fips
ubuntulinux-fips
ubuntulinux-gcp
ubuntulinux-gcp-6.8
ubuntulinux-gcp-fips

CVSS provenance

nvdv3.18.1HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
vendor_redhat7.0MEDIUM
vendor_ubuntu2.0LOW
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