CVE-2026-98405
Published Oct 14, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix missing iov bounds check in parse_posix_sids() In parse_posix_sids(), sidsbuf_end is calculated using the server-supplied out_len without being validated against the actual length of the received iov (iov_len). If a server provides an inflated out_len, sidsbuf_end will point past the end of the iov. This defeats the bounds guards in posix_info_sid_size(), allowing out-of-bounds reads into adjacent kernel memory. Fix this by rejecting responses where the calculated sidsbuf_end would exceed the received iov boundaries or cause pointer wraparound.
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References
Other References
https://git.kernel.org/stable/c/2f8ed71aaaba3bc8b19cd9930cc62e63e142b299
https://git.kernel.org/stable/c/b09d092eb24ad0110f16a9b7c1ed5d2a0c1733dc
https://git.kernel.org/stable/c/b862996e5105be1293da9cdc85da77b76021c3bd
https://git.kernel.org/stable/c/d91b9a3b2b38e5ac1b51e9e5b23fe53ad7b49644
https://git.kernel.org/stable/c/eac6917a42899aad0617bbf04798c5dd946a1fe5
Frequently Asked Questions
What is CVE-2026-98405? +
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix missing iov bounds check in parse_posix_sids()
In parse_posix_sids(), sidsbuf_end is calculated using the server-supplied
out_len without being validated against the actual length of the received
iov (iov_len).
If a server provides an inflated out_len, sidsbuf_end will point past the
end of the iov. This defeats the bounds guards in posix_info_sid_size(),
allowing out-of-bounds reads into adjacent kernel memory.
Fix this by rejecting responses where the calculated sidsbuf_end would
exceed the received iov boundaries or cause pointer wraparound.
How do I check if I'm vulnerable to CVE-2026-98405? +
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.