CVE-2025-40099
Published Oct 30, 2025
Modified Apr 15, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: cifs: parse_dfs_referrals: prevent oob on malformed input Malicious SMB server can send invalid reply to FSCTL_DFS_GET_REFERRALS - reply smaller than sizeof(struct get_dfs_referral_rsp) - reply with number of referrals smaller than NumberOfReferrals in the header Processing of such replies will cause oob. Return -EINVAL error on such replies to prevent oob-s.
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References
Other References
https://git.kernel.org/stable/c/15c73964da9df994302f579ed14ee5fdbce7a332
https://git.kernel.org/stable/c/6447b0e355562a1ff748c4a2ffb89aae7e84d2c9
https://git.kernel.org/stable/c/8bc4a8d39bac23d8b044fd3e2dbfd965f1d9b058
https://git.kernel.org/stable/c/bb0f2e66e1ac043a5b238f5bcab4f26f3c317039
https://git.kernel.org/stable/c/cfacc7441f760e4a73cc71b6ff1635261d534657
Frequently Asked Questions
What is CVE-2025-40099? +
In the Linux kernel, the following vulnerability has been resolved:
cifs: parse_dfs_referrals: prevent oob on malformed input
Malicious SMB server can send invalid reply to FSCTL_DFS_GET_REFERRALS
- reply smaller than sizeof(struct get_dfs_referral_rsp)
- reply with number of referrals smaller than NumberOfReferrals in the
header
Processing of such replies will cause oob.
Return -EINVAL error on such replies to prevent oob-s.
How do I check if I'm vulnerable to CVE-2025-40099? +
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.