CVE-2026-99113
Received
Received - Intake
Memory Corruption in Linux Kernel ksmbd SMB Server
Vulnerability report for CVE-2026-99113, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-28
Last updated on: 2026-10-28
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in
smb2_get_info_filesystem() reports 64 bytes for FS_OBJECT_ID_INFORMATION,
that is the whole of struct object_id_info, but writes only 46 of them:
- objid[] is 16 bytes, and when the volume UUID is not available only
sizeof(stfs.f_fsid) (8) bytes are copied into it;
- extended_info.version_string[] is STRING_LENGTH (28) bytes, and only
strlen("1.1.0") (5) bytes are copied into it.
The response buffer is zeroed on allocation (kvzalloc() in
smb2_allocate_rsp_buf()), so for a standalone request the remaining 31
bytes are zero. In a compound request they need not be. The offset of
the next response is advanced by the length pinned for the previous one,
so if a preceding command wrote its reply into the buffer and then
failed, smb2_set_err_rsp() pins only the short error response and the
next reply lands inside the area that has already been written. Only
the header is cleared there:
memset((char *)rsp_hdr, 0, sizeof(struct smb2_hdr) + 2);
The client then receives up to 31 bytes of a response it was not meant
to see, including one that failed with an access denied error.
Clear the structure before filling it in. As a side effect
version_string is now NUL terminated.
CVSS Scores
EPSS Scores
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Meta Information
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
