CVE-2026-90153

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-90153", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.789Z", "datePublished": "2026-09-17T16:06:46.296Z", "dateUpdated": "2026-10-30T12:34:27.032Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:34:27.032Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: bound smb_check_perm_dacl() ACE walks by DACL size\n\nsmb_check_perm_dacl() validates that the DACL fits inside the NT\nsecurity descriptor, but then bounds its two ACE walks by the\nremaining NTSD length (acl_size) rather than the DACL's declared\nsize (pdacl_size).\n\nWhen pdacl->size is smaller than the trailing NTSD buffer, bytes\nafter the declared DACL boundary - still inside the stored security\ndescriptor - are parsed as ACEs during access checks. A crafted\nDACL can place an access-granting ACE beyond pdacl->size, and the\ncurrent code accepts it during SMB2_CREATE access validation, while\nparse_dacl() and smb_inherit_dacl() stop at pdacl_size.\n\nBound both ACE walks by pdacl_size to match the DACL boundary\nsemantics used elsewhere in the server.\n\nValidation:\n- semantic KUnit harness shows the post-boundary ACE is selected\n before the fix and rejected (EACCES) after it\n- linux master (7.2-rc6), x86_64"}], "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:N", "baseScore": 8.1, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - The crafted NTSD is carried in SMB2_SET_INFO (SMB2_O_INFO_SECURITY) or an SMB2_CREATE SMB2_CREATE_SD_BUFFER context; set_info_sec()/ksmbd_vfs_set_sd_xattr() store that buffer, and a later SMB2_CREATE in smb2_open() loads it into smb_check_perm_dacl() from ksmbd_conn_handler_loop() on TCP/445.\nAC:L - The attacker sets pdacl->size smaller than the NTSD tail, inflates num_aces, and places an ACCESS_ALLOWED ACE after the declared DACL; smb_check_perm_dacl() then walks those bytes on the next SMB2_CREATE with no race or attacker-uncontrollable layout.\nPR:L - __handle_ksmbd_work() requires check_user_session()/get_ksmbd_tcon() before smb2_open()/smb2_set_info(); planting the NTSD needs FILE_WRITE_DAC/FILE_WRITE_OWNER in smb2_set_info_sec() or create rights for SMB2_CREATE_SD_BUFFER on an acl-xattr share, not a pre-auth path.\nUI:N - The attacker alone sends the SMB2_SET_INFO or SMB2_CREATE SD_BUFFER that stores the NTSD and the SMB2_CREATE that calls smb_check_perm_dacl(); no victim mount, open, or other interactive step is required.\nS:U - smb_check_perm_dacl() only mis-evaluates the stored DACL for ksmbd file opens; the resulting access grant stays inside the kernel SMB server and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - The SID-matching ACE walk in smb_check_perm_dacl() can select a post-pdacl->size ACCESS_ALLOWED ACE for the caller or Everyone and apply its access_req, so SMB2_CREATE is authorized for FILE_READ_DATA that the declared DACL would have denied with -EACCES.\nI:H - The same extra ACE supplies attacker-controlled ace->access_req; ACCESS_ALLOWED with FILE_WRITE_DATA/GENERIC_ALL makes smb_check_perm_dacl() accept a write SMB2_CREATE that parse_dacl() and smb_inherit_dacl() never grant from the bounded DACL.\nA:N - Both walks stay inside the NTSD (acl_size from pntsd_size); the bug only returns success instead of -EACCES and does not oops, panic, hang, or corrupt memory."}]}], "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": "8f0541186e9ad1b62accc9519cc2b7a7240272a7", "lessThan": "930dcdd888eabf166589e020dcbf6d15b5e13305", "status": "affected", "versionType": "git"}, {"version": "8f0541186e9ad1b62accc9519cc2b7a7240272a7", "lessThan": "a2051ffe452afad52f580b85a3fd8851933b1e7c", "status": "affected", "versionType": "git"}, {"version": "8f0541186e9ad1b62accc9519cc2b7a7240272a7", "lessThan": "a29f57a14c939586d84d7fd6a029bd1fd170098f", "status": "affected", "versionType": "git"}, {"version": "8f0541186e9ad1b62accc9519cc2b7a7240272a7", "lessThan": "a4a307d149327dad5fb25187e1b03cebd1b04de6", "status": "affected", "versionType": "git"}, {"version": "8f0541186e9ad1b62accc9519cc2b7a7240272a7", "lessThan": "8e4f75e979c1d9a51b0a48ac33d0cfd5f039ec67", "status": "affected", "versionType": "git"}, {"version": "8f0541186e9ad1b62accc9519cc2b7a7240272a7", "lessThan": "79decd88dd3f0d42e7fb0689b1a7853bfa302459", "status": "affected", "versionType": "git"}, {"version": "cb69d4d6f709f87c94afa28ae64c501576692171", "status": "affected", "versionType": "git"}, {"version": "6e8f4abf584253cbaa596ea4ad13110cf61cd4c9", "status": "affected", "versionType": "git"}, {"version": "8e33102309bd6839b2e2e158f93a7b378cb4655d", "status": "affected", "versionType": "git"}, {"version": "5.15.62", "lessThan": "5.16", "status": "affected", "versionType": "semver"}, {"version": "5.18.18", "lessThan": "5.19", "status": "affected", "versionType": "semver"}, {"version": "5.19.2", "lessThan": "5.20", "status": "affected", "versionType": "semver"}]}, {"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": "6.0", "status": "affected"}, {"version": "0", "lessThan": "6.0", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.191", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "6.0", "versionEndExcluding": "6.1.191"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.6.157"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.12.110"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.18.52"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "7.2.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "7.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.62"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18.18"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/930dcdd888eabf166589e020dcbf6d15b5e13305"}, {"url": "https://git.kernel.org/stable/c/a2051ffe452afad52f580b85a3fd8851933b1e7c"}, {"url": "https://git.kernel.org/stable/c/a29f57a14c939586d84d7fd6a029bd1fd170098f"}, {"url": "https://git.kernel.org/stable/c/a4a307d149327dad5fb25187e1b03cebd1b04de6"}, {"url": "https://git.kernel.org/stable/c/8e4f75e979c1d9a51b0a48ac33d0cfd5f039ec67"}, {"url": "https://git.kernel.org/stable/c/79decd88dd3f0d42e7fb0689b1a7853bfa302459"}], "title": "ksmbd: bound smb_check_perm_dacl() ACE walks by DACL size", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"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": "930dcdd888eabf166589e020dcbf6d15b5e13305", "status": "affected", "version": "8f0541186e9ad1b62accc9519cc2b7a7240272a7", "versionType": "git"}, {"lessThan": "a2051ffe452afad52f580b85a3fd8851933b1e7c", "status": "affected", "version": "8f0541186e9ad1b62accc9519cc2b7a7240272a7", "versionType": "git"}, {"lessThan": "a29f57a14c939586d84d7fd6a029bd1fd170098f", "status": "affected", "version": "8f0541186e9ad1b62accc9519cc2b7a7240272a7", "versionType": "git"}, {"lessThan": "a4a307d149327dad5fb25187e1b03cebd1b04de6", "status": "affected", "version": "8f0541186e9ad1b62accc9519cc2b7a7240272a7", "versionType": "git"}, {"lessThan": "8e4f75e979c1d9a51b0a48ac33d0cfd5f039ec67", "status": "affected", "version": "8f0541186e9ad1b62accc9519cc2b7a7240272a7", "versionType": "git"}, {"lessThan": "79decd88dd3f0d42e7fb0689b1a7853bfa302459", "status": "affected", "version": "8f0541186e9ad1b62accc9519cc2b7a7240272a7", "versionType": "git"}, {"status": "affected", "version": "cb69d4d6f709f87c94afa28ae64c501576692171", "versionType": "git"}, {"status": "affected", "version": "6e8f4abf584253cbaa596ea4ad13110cf61cd4c9", "versionType": "git"}, {"status": "affected", "version": "8e33102309bd6839b2e2e158f93a7b378cb4655d", "versionType": "git"}, {"lessThan": "5.16", "status": "affected", "version": "5.15.62", "versionType": "semver"}, {"lessThan": "5.19", "status": "affected", "version": "5.18.18", "versionType": "semver"}, {"lessThan": "5.20", "status": "affected", "version": "5.19.2", "versionType": "semver"}]}, {"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": "6.0"}, {"lessThan": "6.0", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.191", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.157", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.110", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.52", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.6", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "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: bound smb_check_perm_dacl() ACE walks by DACL size\n\nsmb_check_perm_dacl() validates that the DACL fits inside the NT\nsecurity descriptor, but then bounds its two ACE walks by the\nremaining NTSD length (acl_size) rather than the DACL's declared\nsize (pdacl_size).\n\nWhen pdacl->size is smaller than the trailing NTSD buffer, bytes\nafter the declared DACL boundary - still inside the stored security\ndescriptor - are parsed as ACEs during access checks. A crafted\nDACL can place an access-granting ACE beyond pdacl->size, and the\ncurrent code accepts it during SMB2_CREATE access validation, while\nparse_dacl() and smb_inherit_dacl() stop at pdacl_size.\n\nBound both ACE walks by pdacl_size to match the DACL boundary\nsemantics used elsewhere in the server.\n\nValidation:\n- semantic KUnit harness shows the post-boundary ACE is selected\n before the fix and rejected (EACCES) after it\n- linux master (7.2-rc6), x86_64"}], "id": "CVE-2026-90153", "lastModified": "2026-10-30T13:20:43.860", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 5.2, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-17T17:17:08.370", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/79decd88dd3f0d42e7fb0689b1a7853bfa302459"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8e4f75e979c1d9a51b0a48ac33d0cfd5f039ec67"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/930dcdd888eabf166589e020dcbf6d15b5e13305"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a2051ffe452afad52f580b85a3fd8851933b1e7c"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a29f57a14c939586d84d7fd6a029bd1fd170098f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a4a307d149327dad5fb25187e1b03cebd1b04de6"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8f0541186e9ad1b62accc9519cc2b7a7240272a7,a2051ffe452afad52f580b85a3fd8851933b1e7c)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8f0541186e9ad1b62accc9519cc2b7a7240272a7,a29f57a14c939586d84d7fd6a029bd1fd170098f)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8f0541186e9ad1b62accc9519cc2b7a7240272a7,a4a307d149327dad5fb25187e1b03cebd1b04de)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8f0541186e9ad1b62accc9519cc2b7a7240272a7,8e4f75e979c1d9a51b0a48ac33d0cfd5f039ec67)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8f0541186e9ad1b62accc9519cc2b7a7240272a7,79decd88dd3f0d42e7fb0689b1a7853bfa302459)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "cb69d4d6f709f87c94afa28ae64c501576692171"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "6e8f4abf584253cbaa596ea4ad13110cf61cd4c9"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "8e33102309bd6839b2e158f93a7b378cb4655d"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.15.62,5.16)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.18.18,5.19)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.19.2,5.20)"}}], "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": "affected", "versions": {"scheme": "semver", "value": "6.0"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.157,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.110,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.52,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.6,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc1,*]"}}], "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": "2026-09-18T18:45:12.441113+00:00", "updated": "2026-09-20T02:00:13.594671+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-125", "CWE-122"]}