{"id":"CVE-2026-53396","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix posix_acl leak and ignored error in nfsd4_create_file\n\nnfsd4_create_file() has two bugs in its ACL handling:\n\nThe return value of nfsd4_acl_to_attr() is silen…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix posix_acl leak and ignored error in nfsd4_create_file\n\nnfsd4_create_file() has two bugs in its ACL handling:\n\nThe return value of nfsd4_acl_to_attr() is silen…","severity":"none","published":"2026-07-19","updated":"2026-07-19","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53396","references":[{"url":"https://git.kernel.org/stable/c/18cf006a08babec0bbac2a3784f8f28e56e47490","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/24c975bbdd564d7d0ad90294bfa69729830345de","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"ingestedAt":"2026-07-19T21:33:34.925Z","epss":0.0038,"epssPercentile":0.31878,"slug":"CVE-2026-53396","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix posix_acl leak and ignored error in nfsd4_create_file\n\nnfsd4_create_file() has two bugs in its ACL handling:\n\nThe return value of nfsd4_acl_to_attr() is silently discarded.  When\nthe NFSv4-to-POSIX ACL conversion fails (e.g., -EINVAL for\nunsupported ACE types), the file is created without any ACL and the\nclient receives NFS4_OK.  This violates RFC 7530/8881 which require\nthe server to reject unsupported attributes on CREATE.\n\nWhen start_creating() fails after ACL attributes have been populated\nin attrs (either via nfsd4_acl_to_attr or via ownership transfer from\nopen->op_dpacl/op_pacl), the function jumps to out_write which skips\nnfsd_attrs_free().  The posix_acl allocations are leaked.  A client\ncan trigger this repeatedly with OPEN(CREATE), ACL attributes, and an\ninvalid filename (e.g., longer than NAME_MAX).\n\nFix both by capturing the nfsd4_acl_to_attr() return value and by\nchanging the early error paths to jump to out instead of out_write.\nInitialize child to ERR_PTR(-EINVAL) so that end_creating() is safe\nto call even if start_creating() was never reached.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}