CVE-2026-98686
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 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.
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References
Other References
Frequently Asked Questions
What is CVE-2026-98686? +
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.
How do I check if I'm vulnerable to CVE-2026-98686? +
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.