CVE-2026-68100

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-68100", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.368Z", "datePublished": "2026-08-10T11:58:15.233Z", "dateUpdated": "2026-10-19T20:58:50.348Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:45:50.170Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate num_subauth when copying ACE in set_ntacl_dacl\n\nset_ntacl_dacl() copies each ACE from the attacker-controlled stored\nsecurity descriptor verbatim into the response DACL without checking\nsid.num_subauth. The ACE bytes (including an unchecked num_subauth)\noriginate from an authenticated SMB2_SET_INFO(SecInfo=DACL) that is\nstored raw via ksmbd_vfs_set_sd_xattr(); parse_dacl() rejects a bad ACE\nwith `break` rather than an error, so parse_sec_desc() still returns\nsuccess and the malformed SD reaches the xattr intact.\n\nOn a subsequent SMB2_QUERY_INFO(SecInfo=DACL) for an inode carrying a\nPOSIX access ACL, build_sec_desc() -> set_ntacl_dacl() ->\nset_posix_acl_entries_dacl() walks the copied ACEs and reads\n\n ntace->sid.sub_auth[ntace->sid.num_subauth - 1]\n\nwith num_subauth taken straight from the stored SD. Since sub_auth[]\nis fixed at SID_MAX_SUB_AUTHORITIES (15), a crafted num_subauth (e.g.\n255) drives an out-of-bounds heap read of ~1 KB with an offset fully\ncontrolled by an authenticated client.\n\nThe sibling functions already gate this field:\n parse_dacl() -- num_subauth == 0 || > SID_MAX_SUB_AUTHORITIES\n parse_sid() -- num_subauth > SID_MAX_SUB_AUTHORITIES\n smb_copy_sid() -- min_t(u8, num_subauth, SID_MAX_SUB_AUTHORITIES)\nset_ntacl_dacl() is the lone inconsistent path that omits the check.\n\nAdd the same num_subauth validation in set_ntacl_dacl() before copying\nthe ACE, matching the gate already enforced by parse_dacl()."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 8.1, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - ksmbd is the in-kernel SMB3 server on TCP/445; both SMB2_SET_INFO(SecInfo=DACL) and SMB2_QUERY_INFO(SecInfo=DACL) are handled from remote SMB2 PDUs in smb2_set_info()/smb2_query_info() via ksmbd_conn_handler_loop(), with no local syscall or physical access required.\nAC:L - Once ksmbd is running with ACL-xattr shares, an attacker deterministically plants a malformed DACL via SET_INFO and triggers the read on QUERY_INFO; num_subauth fully controls the OOB offset, with no race, timing window, or victim-dependent memory layout required.\nPR:L - SMB2_SET_INFO/QUERY_INFO require a valid post-authentication session (smb2_check_user_session) and SET_INFO SECURITY additionally requires FILE_WRITE_DAC/FILE_WRITE_OWNER on the open handle; this is a low-privilege authenticated SMB client, not a pre-auth or root-only path.\nUI:N - Exploitation is driven entirely by the attacker's own SMB2 SET_INFO and QUERY_INFO requests over the network; no local user, administrator, or victim client must perform any separate action.\nS:U - The out-of-bounds read and any resulting disclosure or crash occur entirely within kernel ksmbd server memory on the host; no VM, IOMMU, container, or other security-boundary escape is involved.\nC:H - Crafted num_subauth (e.g. 255) makes set_posix_acl_entries_dacl() index far past the 15-element sub_auth[] array, performing an attacker-offset-controlled ~1 KB out-of-bounds kernel heap read whose value is compared during DACL rebuild, enabling kernel memory disclosure.\nI:N - The defect is an out-of-bounds read during ACE deduplication; no kernel memory is written, no attacker-controlled data is persisted beyond the intentionally stored security descriptor, and no code-execution or arbitrary-write primitive is introduced.\nA:H - An unchecked multi-hundred-byte read past the smb_ace SID sub_auth array can cross slab/object boundaries and fault on hardened or KASAN builds; any unvalidated kernel out-of-bounds access is treated as capable of oops/panic and full host denial of service."}]}], "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": "26cb845e22a00c85bf566337417fa33492395f10", "status": "affected", "versionType": "git"}, {"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "e31fada5143784bc05c7ae44c79eed9b7a2e147e", "status": "affected", "versionType": "git"}, {"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "fb3dc8e6da46a1ccad1956cda57de29d9b3033e0", "status": "affected", "versionType": "git"}, {"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "b6d3cc6a524416dfdb2b47e4bba2e7e20011d056", "status": "affected", "versionType": "git"}, {"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "5acbd3012fd4a7ccfebd91ea6f784120084eb897", "status": "affected", "versionType": "git"}, {"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "47f0b34f6bc98ed85bfdc293e8f3e432ec24958d", "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": "6.1.184", "lessThanOrEqual": "6.1.*", "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": "6.1.184"}, {"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/26cb845e22a00c85bf566337417fa33492395f10"}, {"url": "https://git.kernel.org/stable/c/e31fada5143784bc05c7ae44c79eed9b7a2e147e"}, {"url": "https://git.kernel.org/stable/c/fb3dc8e6da46a1ccad1956cda57de29d9b3033e0"}, {"url": "https://git.kernel.org/stable/c/b6d3cc6a524416dfdb2b47e4bba2e7e20011d056"}, {"url": "https://git.kernel.org/stable/c/5acbd3012fd4a7ccfebd91ea6f784120084eb897"}, {"url": "https://git.kernel.org/stable/c/47f0b34f6bc98ed85bfdc293e8f3e432ec24958d"}], "title": "ksmbd: validate num_subauth when copying ACE in set_ntacl_dacl", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-68100", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-16T15:43:46.339201Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-125", "description": "CWE-125 Out-of-bounds Read"}]}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-19T20:58:50.348Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-68100", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-16T15:43:46.339201Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-125", "description": "CWE-125 Out-of-bounds Read"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T15:43:47.131Z"}}], "cna": {"title": "ksmbd: validate num_subauth when copying ACE in set_ntacl_dacl", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 8.1, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - ksmbd is the in-kernel SMB3 server on TCP/445; both SMB2_SET_INFO(SecInfo=DACL) and SMB2_QUERY_INFO(SecInfo=DACL) are handled from remote SMB2 PDUs in smb2_set_info()/smb2_query_info() via ksmbd_conn_handler_loop(), with no local syscall or physical access required.\nAC:L - Once ksmbd is running with ACL-xattr shares, an attacker deterministically plants a malformed DACL via SET_INFO and triggers the read on QUERY_INFO; num_subauth fully controls the OOB offset, with no race, timing window, or victim-dependent memory layout required.\nPR:L - SMB2_SET_INFO/QUERY_INFO require a valid post-authentication session (smb2_check_user_session) and SET_INFO SECURITY additionally requires FILE_WRITE_DAC/FILE_WRITE_OWNER on the open handle; this is a low-privilege authenticated SMB client, not a pre-auth or root-only path.\nUI:N - Exploitation is driven entirely by the attacker's own SMB2 SET_INFO and QUERY_INFO requests over the network; no local user, administrator, or victim client must perform any separate action.\nS:U - The out-of-bounds read and any resulting disclosure or crash occur entirely within kernel ksmbd server memory on the host; no VM, IOMMU, container, or other security-boundary escape is involved.\nC:H - Crafted num_subauth (e.g. 255) makes set_posix_acl_entries_dacl() index far past the 15-element sub_auth[] array, performing an attacker-offset-controlled ~1 KB out-of-bounds kernel heap read whose value is compared during DACL rebuild, enabling kernel memory disclosure.\nI:N - The defect is an out-of-bounds read during ACE deduplication; no kernel memory is written, no attacker-controlled data is persisted beyond the intentionally stored security descriptor, and no code-execution or arbitrary-write primitive is introduced.\nA:H - An unchecked multi-hundred-byte read past the smb_ace SID sub_auth array can cross slab/object boundaries and fault on hardened or KASAN builds; any unvalidated kernel out-of-bounds access is treated as capable of oops/panic and full host denial of service."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "26cb845e22a00c85bf566337417fa33492395f10", "versionType": "git"}, {"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "e31fada5143784bc05c7ae44c79eed9b7a2e147e", "versionType": "git"}, {"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "fb3dc8e6da46a1ccad1956cda57de29d9b3033e0", "versionType": "git"}, {"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "b6d3cc6a524416dfdb2b47e4bba2e7e20011d056", "versionType": "git"}, {"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "5acbd3012fd4a7ccfebd91ea6f784120084eb897", "versionType": "git"}, {"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "47f0b34f6bc98ed85bfdc293e8f3e432ec24958d", "versionType": "git"}], "programFiles": ["fs/smb/server/smbacl.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.15"}, {"status": "unaffected", "version": "0", "lessThan": "5.15", "versionType": "semver"}, {"status": "unaffected", "version": "6.1.184", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.148", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.101", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.42", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.1.6", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["fs/smb/server/smbacl.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/26cb845e22a00c85bf566337417fa33492395f10"}, {"url": "https://git.kernel.org/stable/c/e31fada5143784bc05c7ae44c79eed9b7a2e147e"}, {"url": "https://git.kernel.org/stable/c/fb3dc8e6da46a1ccad1956cda57de29d9b3033e0"}, {"url": "https://git.kernel.org/stable/c/b6d3cc6a524416dfdb2b47e4bba2e7e20011d056"}, {"url": "https://git.kernel.org/stable/c/5acbd3012fd4a7ccfebd91ea6f784120084eb897"}, {"url": "https://git.kernel.org/stable/c/47f0b34f6bc98ed85bfdc293e8f3e432ec24958d"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate num_subauth when copying ACE in set_ntacl_dacl\n\nset_ntacl_dacl() copies each ACE from the attacker-controlled stored\nsecurity descriptor verbatim into the response DACL without checking\nsid.num_subauth. The ACE bytes (including an unchecked num_subauth)\noriginate from an authenticated SMB2_SET_INFO(SecInfo=DACL) that is\nstored raw via ksmbd_vfs_set_sd_xattr(); parse_dacl() rejects a bad ACE\nwith `break` rather than an error, so parse_sec_desc() still returns\nsuccess and the malformed SD reaches the xattr intact.\n\nOn a subsequent SMB2_QUERY_INFO(SecInfo=DACL) for an inode carrying a\nPOSIX access ACL, build_sec_desc() -> set_ntacl_dacl() ->\nset_posix_acl_entries_dacl() walks the copied ACEs and reads\n\n ntace->sid.sub_auth[ntace->sid.num_subauth - 1]\n\nwith num_subauth taken straight from the stored SD. Since sub_auth[]\nis fixed at SID_MAX_SUB_AUTHORITIES (15), a crafted num_subauth (e.g.\n255) drives an out-of-bounds heap read of ~1 KB with an offset fully\ncontrolled by an authenticated client.\n\nThe sibling functions already gate this field:\n parse_dacl() -- num_subauth == 0 || > SID_MAX_SUB_AUTHORITIES\n parse_sid() -- num_subauth > SID_MAX_SUB_AUTHORITIES\n smb_copy_sid() -- min_t(u8, num_subauth, SID_MAX_SUB_AUTHORITIES)\nset_ntacl_dacl() is the lone inconsistent path that omits the check.\n\nAdd the same num_subauth validation in set_ntacl_dacl() before copying\nthe ACE, matching the gate already enforced by parse_dacl()."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.184", "versionStartIncluding": "5.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.148", "versionStartIncluding": "5.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.101", "versionStartIncluding": "5.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.42", "versionStartIncluding": "5.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1.6", "versionStartIncluding": "5.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2", "versionStartIncluding": "5.15"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:45:50.170Z"}}}, "cveMetadata": {"cveId": "CVE-2026-68100", "state": "PUBLISHED", "dateUpdated": "2026-10-19T20:58:50.348Z", "dateReserved": "2026-07-30T09:28:09.368Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-08-10T11:58:15.233Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/smb/server/smbacl.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "26cb845e22a00c85bf566337417fa33492395f10", "status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "versionType": "git"}, {"lessThan": "e31fada5143784bc05c7ae44c79eed9b7a2e147e", "status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "versionType": "git"}, {"lessThan": "fb3dc8e6da46a1ccad1956cda57de29d9b3033e0", "status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "versionType": "git"}, {"lessThan": "b6d3cc6a524416dfdb2b47e4bba2e7e20011d056", "status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "versionType": "git"}, {"lessThan": "5acbd3012fd4a7ccfebd91ea6f784120084eb897", "status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "versionType": "git"}, {"lessThan": "47f0b34f6bc98ed85bfdc293e8f3e432ec24958d", "status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/smb/server/smbacl.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.15"}, {"lessThan": "5.15", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.184", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.148", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.101", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.42", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.6", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate num_subauth when copying ACE in set_ntacl_dacl\n\nset_ntacl_dacl() copies each ACE from the attacker-controlled stored\nsecurity descriptor verbatim into the response DACL without checking\nsid.num_subauth. The ACE bytes (including an unchecked num_subauth)\noriginate from an authenticated SMB2_SET_INFO(SecInfo=DACL) that is\nstored raw via ksmbd_vfs_set_sd_xattr(); parse_dacl() rejects a bad ACE\nwith `break` rather than an error, so parse_sec_desc() still returns\nsuccess and the malformed SD reaches the xattr intact.\n\nOn a subsequent SMB2_QUERY_INFO(SecInfo=DACL) for an inode carrying a\nPOSIX access ACL, build_sec_desc() -> set_ntacl_dacl() ->\nset_posix_acl_entries_dacl() walks the copied ACEs and reads\n\n ntace->sid.sub_auth[ntace->sid.num_subauth - 1]\n\nwith num_subauth taken straight from the stored SD. Since sub_auth[]\nis fixed at SID_MAX_SUB_AUTHORITIES (15), a crafted num_subauth (e.g.\n255) drives an out-of-bounds heap read of ~1 KB with an offset fully\ncontrolled by an authenticated client.\n\nThe sibling functions already gate this field:\n parse_dacl() -- num_subauth == 0 || > SID_MAX_SUB_AUTHORITIES\n parse_sid() -- num_subauth > SID_MAX_SUB_AUTHORITIES\n smb_copy_sid() -- min_t(u8, num_subauth, SID_MAX_SUB_AUTHORITIES)\nset_ntacl_dacl() is the lone inconsistent path that omits the check.\n\nAdd the same num_subauth validation in set_ntacl_dacl() before copying\nthe ACE, matching the gate already enforced by parse_dacl()."}], "id": "CVE-2026-68100", "lastModified": "2026-10-19T21:17:50.707", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 5.2, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-68100", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T15:43:46.339201Z", "version": "2.0.3"}}]}, "published": "2026-08-10T13:19:54.533", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/26cb845e22a00c85bf566337417fa33492395f10"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/47f0b34f6bc98ed85bfdc293e8f3e432ec24958d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5acbd3012fd4a7ccfebd91ea6f784120084eb897"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b6d3cc6a524416dfdb2b47e4bba2e7e20011d056"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e31fada5143784bc05c7ae44c79eed9b7a2e147e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fb3dc8e6da46a1ccad1956cda57de29d9b3033e0"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-125"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "kernel: Linux kernel ksmbd: Information disclosure via out-of-bounds read", "id": "2513393", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2513393"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.9", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H", "status": "draft"}, "cwe": "CWE-125", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nksmbd: validate num_subauth when copying ACE in set_ntacl_dacl\nset_ntacl_dacl() copies each ACE from the attacker-controlled stored\nsecurity descriptor verbatim into the response DACL without checking\nsid.num_subauth. The ACE bytes (including an unchecked num_subauth)\noriginate from an authenticated SMB2_SET_INFO(SecInfo=DACL) that is\nstored raw via ksmbd_vfs_set_sd_xattr(); parse_dacl() rejects a bad ACE\nwith `break` rather than an error, so parse_sec_desc() still returns\nsuccess and the malformed SD reaches the xattr intact.\nOn a subsequent SMB2_QUERY_INFO(SecInfo=DACL) for an inode carrying a\nPOSIX access ACL, build_sec_desc() -> set_ntacl_dacl() ->\nset_posix_acl_entries_dacl() walks the copied ACEs and reads\nntace->sid.sub_auth[ntace->sid.num_subauth - 1]\nwith num_subauth taken straight from the stored SD. Since sub_auth[]\nis fixed at SID_MAX_SUB_AUTHORITIES (15), a crafted num_subauth (e.g.\n255) drives an out-of-bounds heap read of ~1 KB with an offset fully\ncontrolled by an authenticated client.\nThe sibling functions already gate this field:\nparse_dacl() -- num_subauth == 0 || > SID_MAX_SUB_AUTHORITIES\nparse_sid() -- num_subauth > SID_MAX_SUB_AUTHORITIES\nsmb_copy_sid() -- min_t(u8, num_subauth, SID_MAX_SUB_AUTHORITIES)\nset_ntacl_dacl() is the lone inconsistent path that omits the check.\nAdd the same num_subauth validation in set_ntacl_dacl() before copying\nthe ACE, matching the gate already enforced by parse_dacl().", "A flaw was found in ksmbd in the Linux kernel. An authenticated client can provide a crafted security descriptor that is not properly validated when copying Access Control Entries (ACEs) in the `set_ntacl_dacl()` function. This improper validation leads to an out-of-bounds heap read, allowing the client to read approximately 1 KB of kernel memory. This could result in the disclosure of sensitive information."], "name": "CVE-2026-68100", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:enterprise_linux_nvidia:", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux for NVIDIA 26"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Affected", "package_name": "rhcos", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-08-10T11:58:15Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-68100\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-68100\nhttps://git.kernel.org/stable/c/47f0b34f6bc98ed85bfdc293e8f3e432ec24958d\nhttps://git.kernel.org/stable/c/5acbd3012fd4a7ccfebd91ea6f784120084eb897\nhttps://git.kernel.org/stable/c/b6d3cc6a524416dfdb2b47e4bba2e7e20011d056\nhttps://git.kernel.org/stable/c/e31fada5143784bc05c7ae44c79eed9b7a2e147e\nhttps://git.kernel.org/stable/c/fb3dc8e6da46a1ccad1956cda57de29d9b3033e0"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,e31fada5143784bc05c7ae44c79eed9b7a2e147e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,fb3dc8e6da46a1ccad1956cda57de29d9b3033e0)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,b6d3cc6a524416dfdb2b47e4bba2e7e20011d056)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,5acbd3012fd4a7ccfebd91ea6f784120084eb897)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,47f0b34f6bc98ed85bfdc293e8f3e432ec24958d)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.6.148)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.12.101)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.18.42)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,7.1.6)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.148,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.101,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.42,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.6,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2-rc2,*)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-10T13:30:05.188954+00:00", "updated": "2026-08-14T02:30:17.860278+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}