Threaticon
Toggle sidebar

You're viewing a limited, public preview. Log in for full access.

Log in User Guide
Log in Get started
Vulnerabilities CVE-2026-68431

CVE-2026-68431

Critical
Open
TLP:CLEAR

ksmbd: validate minimum PDU size for transform requests

AI Analysis

No AI analysis yet.

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate minimum PDU size for transform requests The receive path applies the minimum SMB2 PDU size check only when ProtocolId is SMB2_PROTO_NUMBER. A packet carrying SMB2_TRANSFORM_PROTO_NUM bypasses the check even when the negotiated dialect does not provide transform handling. On an SMB 2.1 connection, a short transform packet therefore reaches init_smb2_rsp_hdr(), which interprets the request as a full SMB2 header and reads beyond the request allocation. The copied fields can then be returned to the unauthenticated client. Compression transforms are converted to ordinary SMB2 messages before protocol validation. After that conversion, validate ordinary SMB2 requests against SMB2_MIN_SUPPORTED_PDU_SIZE and require encryption transform requests to contain both a transform header and an SMB2 header. This rejects truncated requests before work allocation.

Details

CVSS Score
9.1
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Confidence
90%
Published
Aug 12, 2026
Last Modified
Aug 13, 2026
No notes yet. Click "Add Note" to create the first analysis note.
No opinions yet. Be the first to assess this intelligence.
Leaving Threaticon

This link opens an external site that isn't part of the platform.