{"id":"CVE-2025-40326","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Define actions for the new time_deleg FATTR4 attributes\n\nNFSv4 clients won't send legitimate GETATTR requests for these new\nattributes because they are intended t…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Define actions for the new time_deleg FATTR4 attributes\n\nNFSv4 clients won't send legitimate GETATTR requests for these new\nattributes because they are intended t…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","published":"2025-12-08","updated":"2026-10-14","sourceUpdated":"2026-10-14T22:10:00.210","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-40326","references":[{"url":"https://git.kernel.org/stable/c/4f76435fd517981f01608678c06ad9718a86ee98","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d8f3f94dc950e7c62c96af432c26745885b0a18a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.0035,"epssPercentile":0.26968,"ingestedAt":"2026-10-14T23:00:02.026Z","slug":"CVE-2025-40326","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Define actions for the new time_deleg FATTR4 attributes\n\nNFSv4 clients won't send legitimate GETATTR requests for these new\nattributes because they are intended to be used only with CB_GETATTR\nand SETATTR. But NFSD has to do something besides crashing if it\never sees a GETATTR request that queries these attributes.\n\nRFC 8881 Section 18.7.3 states:\n\n> The server MUST return a value for each attribute that the client\n> requests if the attribute is supported by the server for the\n> target file system. If the server does not support a particular\n> attribute on the target file system, then it MUST NOT return the\n> attribute value and MUST NOT set the attribute bit in the result\n> bitmap. The server MUST return an error if it supports an\n> attribute on the target but cannot obtain its value. In that case,\n> no attribute values will be returned.\n\nFurther, RFC 9754 Section 5 states:\n\n> These new attributes are invalid to be used with GETATTR, VERIFY,\n> and NVERIFY, and they can only be used with CB_GETATTR and SETATTR\n> by a client holding an appropriate delegation.\n\nThus there does not appear to be a specific server response mandated\nby specification. Taking the guidance that querying these attributes\nvia GETATTR is \"invalid\", NFSD will return nfserr_inval, failing the\nrequest entirely.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}