{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-53397", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.402Z", "datePublished": "2026-07-19T12:01:58.938Z", "dateUpdated": "2026-08-17T04:50:49.240Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:50:49.240Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix posix_acl leak on SETACL decode failure\n\nnfsaclsvc_decode_setaclargs() and nfs3svc_decode_setaclargs() each\ncall nfs_stream_decode_acl() twice, first for NFS_ACL and then for\nNFS_DFACL. Each successful call transfers ownership of a freshly\nallocated posix_acl into argp->acl_access or argp->acl_default. If\nthe first call succeeds but the second fails, the decoder returns\nfalse and argp->acl_access is left dangling.\n\nACLPROC2_SETACL.pc_release was wired to nfssvc_release_attrstat and\nACLPROC3_SETACL.pc_release was wired to nfs3svc_release_fhandle.\nBoth only call fh_put() and have no knowledge of the ACL fields on\nargp. The posix_acl_release() pairs sat at the out: labels inside\nnfsacld_proc_setacl() and nfsd3_proc_setacl(), but svc_process()\nskips pc_func when pc_decode returns false, so that cleanup is\nunreachable on decode failure:\n\n svc_process_common()\n pc_decode() /* decode_setaclargs: false */\n /* pc_func skipped */\n pc_release() /* fh_put only -- ACLs leaked */\n\nThe orphaned posix_acl is leaked for the lifetime of the server.\n\nFix by adding nfsaclsvc_release_setacl() and nfs3svc_release_setacl(),\nwhich release both argp->acl_access and argp->acl_default in addition\nto fh_put(), and wiring them as pc_release for their respective SETACL\nprocedures. pc_release runs on every path svc_process() takes after\ndecode, including decode failure, so the posix_acl_release() pairs are\nremoved from the proc functions' out: labels to keep ownership in one\nplace. This matches the existing release_getacl() pattern used by\nthe sibling GETACL procedures." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable code is in nfsd's NFS ACL program (RPC program 100227), reachable over the network via the in-kernel NFS server on TCP/UDP port 2049 when NFSD ACL support is enabled.\nAC:L - Once nfsd with ACL support is running, an attacker can reliably trigger the leak by sending a SETACL RPC with mask including both NFS_ACL and NFS_DFACL, a valid first ACL, and a malformed second ACL that fails decode.\nPR:N - Exploitation requires only network access as an NFS client with RPC credentials (AUTH_UNIX is spoofable) from a source IP matching an export entry; no local shell or real root on the server is needed.\nUI:N - Triggering the leak requires only crafted NFS ACL RPC packets; no victim user action such as mounting a filesystem or opening a file is required.\nS:U - The impact is confined to kernel memory consumption within the nfsd server context and does not cross a security boundary such as a VM, container, or IOMMU isolation boundary.\nC:N - This is a kmalloc leak of attacker-supplied ACL data with no out-of-bounds read, use-after-free, or other mechanism that exposes kernel memory to the attacker.\nI:N - The bug orphans allocated posix_acl objects without modifying file data, ACLs on disk, or any other integrity-protected resources.\nA:H - Each trigger permanently leaks a posix_acl allocation (up to ~16KB with max entries) for the server's lifetime; repeated remote SETACL requests can exhaust kernel memory and deny service to the NFS server and co-hosted workloads." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfsd/nfs2acl.c", "fs/nfsd/nfs3acl.c" ], "versions": [ { "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055", "lessThan": "b2eb1ffd511d1b3c3e21122f97cbbccea411e277", "status": "affected", "versionType": "git" }, { "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055", "lessThan": "b94c4be77682aab06d65ca7296149e3bcfb37353", "status": "affected", "versionType": "git" }, { "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055", "lessThan": "887f92ceccf3eacd5f2402db21254d66372fae00", "status": "affected", "versionType": "git" }, { "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055", "lessThan": "1e96239fddcefacf6afe6c498357be68eacbcabc", "status": "affected", "versionType": "git" }, { "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055", "lessThan": "bd69a825485168ef74e815ecb286754b570fdcc7", "status": "affected", "versionType": "git" }, { "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055", "lessThan": "136b416593f1349cf6f72c8e3d18f0f204ee8545", "status": "affected", "versionType": "git" }, { "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055", "lessThan": "a5b42c1e4ff2befaa6b96f7cbf32174751eba083", "status": "affected", "versionType": "git" }, { "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055", "lessThan": "0853ac544c590880d797b04daa33fcb72b6be0e1", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfsd/nfs2acl.c", "fs/nfsd/nfs3acl.c" ], "versions": [ { "version": "2.6.13", "status": "affected" }, { "version": "0", "lessThan": "2.6.13", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.260", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.211", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.177", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.144", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.95", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.38", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.3", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.13", "versionEndExcluding": "5.10.260" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.13", "versionEndExcluding": "5.15.211" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.13", "versionEndExcluding": "6.1.177" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.13", "versionEndExcluding": "6.6.144" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.13", "versionEndExcluding": "6.12.95" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.13", "versionEndExcluding": "6.18.38" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.13", "versionEndExcluding": "7.1.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.13", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/b2eb1ffd511d1b3c3e21122f97cbbccea411e277" }, { "url": "https://git.kernel.org/stable/c/b94c4be77682aab06d65ca7296149e3bcfb37353" }, { "url": "https://git.kernel.org/stable/c/887f92ceccf3eacd5f2402db21254d66372fae00" }, { "url": "https://git.kernel.org/stable/c/1e96239fddcefacf6afe6c498357be68eacbcabc" }, { "url": "https://git.kernel.org/stable/c/bd69a825485168ef74e815ecb286754b570fdcc7" }, { "url": "https://git.kernel.org/stable/c/136b416593f1349cf6f72c8e3d18f0f204ee8545" }, { "url": "https://git.kernel.org/stable/c/a5b42c1e4ff2befaa6b96f7cbf32174751eba083" }, { "url": "https://git.kernel.org/stable/c/0853ac544c590880d797b04daa33fcb72b6be0e1" } ], "title": "nfsd: fix posix_acl leak on SETACL decode failure", "x_generator": { "engine": "bippy-1.2.0" } } } }