{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68098", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.368Z", "datePublished": "2026-08-10T11:58:12.768Z", "dateUpdated": "2026-08-17T04:58:46.978Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:58:46.978Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: bound DACL dedup walk to copied ACEs\n\nset_ntacl_dacl() can stop copying ACEs before consuming the full input\nDACL when size accounting overflows.\n\nWhen that happens, num_aces reflects only the ACEs that were actually\ncopied into the output DACL, but set_posix_acl_entries_dacl() still\nreceives nt_num_aces and uses it to walk the existing ACE array during\ndedup.\n\nThat makes the dedup walk scan past the copied ACE array and inspect\nbuffer tail that does not contain valid ACEs.\n\nSplit the two meanings currently carried by the NT ACE count. Pass the\nnumber of copied NT ACEs to bound the dedup walk, and preserve the\noriginal \"input DACL had NT ACEs\" state separately for the\nEveryone/default ACL fallback.\n\nThis keeps the dedup walk aligned with the ACEs that are actually\npresent in the rebuilt DACL." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The flaw is in ksmbd's in-kernel SMB server (fs/smb/server/smbacl.c), triggered when a remote client sends SMB2 QUERY_INFO (security descriptor) over TCP/445; build_sec_desc() reads the attacker's stored NTACL xattr and calls set_ntacl_dacl().\nAC:L - An authenticated attacker fully controls the crafted DACL planted via SMB2 SET_INFO and can deterministically trigger partial ACE copy (size overflow) then QUERY_INFO; no race or victim-dependent state is required beyond a file with POSIX ACLs on an ACL-xattr-enabled share.\nPR:L - Exploitation requires a completed SMB2 session and tree connect; planting the malicious security.NTACL xattr needs FILE_WRITE_DAC via SMB2 SET_INFO, and triggering needs an open file handle for QUERY_INFO—standard low-privileged share access, not host root.\nUI:N - The server processes the attacker's SMB2 SET_INFO and QUERY_INFO requests automatically in ksmbd worker threads; no separate local user or administrator action is required beyond normal server operation.\nS:U - Impact is confined to kernel heap memory corruption and ACL processing within the ksmbd server context; it does not cross VM, container, or IOMMU security boundaries.\nC:H - The dedup walk scans past copied ACEs into buffer tail without valid ACE structures, performing out-of-bounds reads including ntace->sid.sub_auth[ntace->sid.num_subauth-1] on attacker-influenced data; per kernel guidance OOB reads score High.\nI:H - Out-of-bounds kernel heap access during the unbounded ACE walk is a memory corruption primitive; incorrect dedup can also append extra ACEs to the rebuilt security descriptor, enabling integrity impact beyond a simple crash.\nA:H - Walking invalid ACE headers (e.g., zero size fields) can hang the dedup loop, and out-of-bounds reads of invalid sid fields can kernel oops/panic, denying SMB service on the affected host." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/smbacl.c" ], "versions": [ { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "6d9d7aa4a2c99c31acfa28921c30b684110cf66c", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "b057a851129c6a084e7e393b62ca3abf6c2660bc", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "f1eba60db813ec28732bf18b5f0a67ebac9c3100", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "a0ebdaa79e10210d4e8ed9fe138e8f4d569719e3", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "58d97fcd0bf1aee694e244cc28635b9df95b543b", "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/smb/server/smbacl.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "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": "5.15", "versionEndExcluding": "6.6.148" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.101" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6d9d7aa4a2c99c31acfa28921c30b684110cf66c" }, { "url": "https://git.kernel.org/stable/c/b057a851129c6a084e7e393b62ca3abf6c2660bc" }, { "url": "https://git.kernel.org/stable/c/f1eba60db813ec28732bf18b5f0a67ebac9c3100" }, { "url": "https://git.kernel.org/stable/c/a0ebdaa79e10210d4e8ed9fe138e8f4d569719e3" }, { "url": "https://git.kernel.org/stable/c/58d97fcd0bf1aee694e244cc28635b9df95b543b" } ], "title": "ksmbd: bound DACL dedup walk to copied ACEs", "x_generator": { "engine": "bippy-1.2.0" } } } }