CVE-2026-98685
Published Oct 18, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: discard post-EOF pagecache when extending a file via clone range cifs_remap_file_range() discarded the pagecache only for the folios overlapping the destination region, so when a clone 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. Start the discard at the smaller of fstart and the old EOF. i_size is still old here, so nothing past the old EOF is flushed to the server.
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References
Frequently Asked Questions
What is CVE-2026-98685? +
In the Linux kernel, the following vulnerability has been resolved:
smb: client: discard post-EOF pagecache when extending a file via clone range
cifs_remap_file_range() discarded the pagecache only for the folios
overlapping the destination region, so when a clone 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.
Start the discard at the smaller of fstart and the old EOF. i_size is
still old here, so nothing past the old EOF is flushed to the server.
How do I check if I'm vulnerable to CVE-2026-98685? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.