{"id":"CVE-2026-89672","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-89672","summary":"nfsd: gate nfs2 setacl by argp->mask","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: gate nfs2 setacl by argp->mask\n\nThe NFSACL v2 SETACL path shares the decoder convention used by its\nv3 sibling: nfsaclsvc_decode_setaclargs() fills in argp->acl_access\nonly when NFS_ACL is set in the request mask and argp->acl_default\nonly when NFS_DFACL is set, leaving the other pointer NULL because\nthe argument buffer is zeroed up to pc_argzero before decode.\n\nnfsacld_proc_setacl() then hands both pointers to set_posix_acl()\nunconditionally. set_posix_acl(idmap, dentry, type, NULL) is the VFS\n\"remove this ACL type\" operation, so an omitted arm is\nindistinguishable from an explicit request to delete that ACL. A\nSETACL carrying only NFS_ACL silently strips the directory's default\nACL; mask=0 strips both.\n\nThis is the same defect just fixed in nfsd3_proc_setacl(); apply the\nsame remedy. Gate each set_posix_acl() call on its mask bit and\ninitialize error to 0 so that a request with neither bit set leaves\nthe on-disk ACLs untouched and returns success. The out_drop_lock\npath and the unconditional posix_acl_release() in\nnfsaclsvc_release_setacl() already tolerate the skipped arms.","published":"2026-09-11T19:45:57.414Z","modified":"2026-09-14T03:46:24.133323994Z","cvss":{"score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.12.109"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/37eea38e7898538f0ec5f1eb8b18d8646e4be41c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a3a7e20ed66d3f04d37883c398da8a113b430769"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e41d173d9dc735cecb15ab7aa63ecab09338f81b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f951b22dbeec46f2e0fba81cb80d1b0c686b61eb"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89672.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89672"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-14T03:46:24.133323994Z"}}