Live › vulnerability › CVE-2026-98454
Go to dashboardThe Linux kernel SMB client parses SMB2/SMB3 create contexts without limiting each record to its Next field, and reads lease contexts at canonical rather than declared offsets. A malicious SMB server or malformed response can therefore make the client read bytes beyond the current context, exposing kernel memory to a handler.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Systems that mount SMB/CIFS shares with the Linux kernel client, especially against servers that are not fully trusted. Systems without the cifs/smb client module loaded or that never mount SMB shares are unlikely to be exposed. The sources do not say which kernel versions are affected.
No product ranges from the sources yet.
uname -r and check whether the kernel includes the fix for smb: client: fix create context out-of-bounds readslsmod | grep -E 'cifs|smb'mount -t cifs,smb3Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix create context out-of-bounds reads
smb2_parse_contexts() validates the complete create-context area but does not limit each record to its Next field before dispatching it. A malformed chain can therefore expose bytes beyond the current context to a handler. The QFid handler also used a full response-structure cast although it only reads DiskFileId.
The SMB2/SMB3 lease parsers made the same layout assumption: they read LeaseState and LeaseFlags at canonical offsets rather than at DataOffset. A valid non-canonical DataOffset could therefore yield unrelated in-bounds data, while a short DataLength was still accepted.
Limit each context to its Next value, reject offsets before the context header, and reject malformed chains. Bound the name range by the current context and do not dispatch a known handler when DataLength is zero. Read the QFid DiskFileId only when the context data covers that field. Parse the lease context from DataOffset and require DataLength to match the v1 or v2 lease_context size used by ksmbd. A size mismatch skips lease parsing without failing the open.
This page as .md · .json · in your agent: get_signal("CVE-2026-98454")
NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.