Live › vulnerability › CVE-2026-98686
Go to dashboardWhen the Linux kernel's SMB client extends a file using zero-range, it leaves pagecache data dirtied past the old end of file in place, so that data becomes visible as file content. The sources describe a data exposure from stale cached pages and do not state an attacker-controlled trigger.
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 running a Linux kernel with the CIFS/SMB3 client that mount SMB shares and use zero-range file extension on files that are also mapped with mmap. Hosts that do not mount SMB shares are unlikely to be affected. Systems without the cifs module loaded can skip it.
No product ranges from the sources yet.
uname -r and compare it against the fixed kernel release in the NVD entry (unknown in the sources).lsmod | grep cifs.Each 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: discard post-EOF pagecache when extending a file via zero range
smb3_zero_range() removed the pagecache only for the range being zeroed, so when it extends the file the folio straddling the old EOF - which may hold data dirtied past EOF through an mmap - was never dropped and became visible as file content once the file was extended.
Lower the discard boundary to the smaller of the zero-range offset and the old EOF.
This page as .md · .json · in your agent: get_signal("CVE-2026-98686")
NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.