CVE-2026-53383

{"id": "CVE-2026-53383", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "eb947403518ea3d93f6d89264bb1f5416bb0c7d0", "lessThan": "25ff12b82a376ff5c4583102a63d2456a6b9ebb9", "versionType": "git"}, {"status": "affected", "version": "854156d12caa9d36de1cf5f084591c7686cc8a9d", "lessThan": "fc578523a72cb8b329d32070b95898e81613cc3f", "versionType": "git"}, {"status": "affected", "version": "5005bcb4219156f1bf7587b185080ec1da08518e", "lessThan": "d2bbbb6c55812220fee5d801c275cc267ea3cbeb", "versionType": "git"}, {"status": "affected", "version": "5005bcb4219156f1bf7587b185080ec1da08518e", "lessThan": "8f0302fb691537d33ec8f668565257ea9d340ffe", "versionType": "git"}, {"status": "affected", "version": "5005bcb4219156f1bf7587b185080ec1da08518e", "lessThan": "7cad3ceaf679c55bc9946685dacafce78ce6b51a", "versionType": "git"}, {"status": "affected", "version": "5005bcb4219156f1bf7587b185080ec1da08518e", "lessThan": "06e1f05a1dbe8bbd054c0927b17fc0a61cc8bef7", "versionType": "git"}, {"status": "affected", "version": "5005bcb4219156f1bf7587b185080ec1da08518e", "lessThan": "5f983b864d3d473ac533b2f4f44a1bbe5dcbccf4", "versionType": "git"}, {"status": "affected", "version": "5005bcb4219156f1bf7587b185080ec1da08518e", "lessThan": "609ca17d869d04ba249e32cdcbf13c0b1c66f43c", "versionType": "git"}, {"status": "affected", "version": "d1066c1b3663401cd23c0d6e60cdae750ce00c0f", "versionType": "git"}, {"status": "affected", "version": "5.15.121", "lessThan": "5.15.211", "versionType": "semver"}, {"status": "affected", "version": "6.1.36", "lessThan": "6.1.177", "versionType": "semver"}, {"status": "affected", "version": "6.3.10", "lessThan": "6.4", "versionType": "semver"}], "programFiles": ["fs/smb/server/smb2pdu.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.4"}, {"status": "unaffected", "version": "0", "lessThan": "6.4", "versionType": "semver"}, {"status": "unaffected", "version": "5.15.211", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.177", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.144", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.95", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.37", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.0.14", "versionType": "semver", "lessThanOrEqual": "7.0.*"}, {"status": "unaffected", "version": "7.1.2", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2-rc1", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["fs/smb/server/smb2pdu.c"], "defaultStatus": "affected"}]}], "published": "2026-07-19T12:16:49.117", "references": [{"url": "https://git.kernel.org/stable/c/06e1f05a1dbe8bbd054c0927b17fc0a61cc8bef7", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/25ff12b82a376ff5c4583102a63d2456a6b9ebb9", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/5f983b864d3d473ac533b2f4f44a1bbe5dcbccf4", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/609ca17d869d04ba249e32cdcbf13c0b1c66f43c", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/7cad3ceaf679c55bc9946685dacafce78ce6b51a", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8f0302fb691537d33ec8f668565257ea9d340ffe", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d2bbbb6c55812220fee5d801c275cc267ea3cbeb", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/fc578523a72cb8b329d32070b95898e81613cc3f", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: reject non-VALID session in compound request branch\n\nsmb2_check_user_session() takes a shortcut for any operation that is not\nthe first in a COMPOUND request: it reuses work->sess (the session bound by\nthe first operation) and validates only the SessionId, then returns\n\"valid\". It never re-checks work->sess->state == SMB2_SESSION_VALID, and a\nSessionId of 0xFFFFFFFFFFFFFFFF (ULLONG_MAX, the MS-SMB2 related-operation\nvalue) skips even the id comparison. The standalone path\n(ksmbd_session_lookup_all() plus the SESSION_SETUP state machine) does\nenforce the VALID state; the compound branch bypasses all of it.\n\nA SESSION_SETUP carrying only an NTLM Type-1 (NtLmNegotiate) blob publishes\na fresh SMB2_SESSION_IN_PROGRESS session whose sess->user is still NULL\n(->user is assigned later, by ntlm_authenticate()). Used as operation 1 of\na COMPOUND with operation 2 = TREE_CONNECT (related, SessionId=ULLONG_MAX,\n\\\\host\\IPC$), the tree-connect then runs on that IN_PROGRESS session and\nreaches ksmbd_ipc_tree_connect_request(), which dereferences\nuser_name(sess->user) with sess->user == NULL (transport_ipc.c:687/701/704)\n-> remote NULL-pointer dereference and a kernel Oops that wedges the ksmbd\nworker for all clients.\n\nReject any non-first compound operation that lands on a session which is\nnot SMB2_SESSION_VALID, mirroring the validity the standalone lookup path\nenforces. SESSION_SETUP itself legitimately runs on an IN_PROGRESS session,\nbut it is never carried as a non-first compound operation, so multi-leg\nauthentication is unaffected by this check."}], "lastModified": "2026-07-29T19:31:47.073", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8B528AA1-AFF4-4B02-BA7F-CE91EBCAA24F", "versionEndExcluding": "5.15.211", "versionStartIncluding": "5.15.121"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C995237F-E217-4A59-BCDF-BC4091A4FA1A", "versionEndExcluding": "6.1.177", "versionStartIncluding": "6.1.36"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3E002324-2B5E-4373-A29E-1D5D0FC97F6F", "versionEndExcluding": "6.4", "versionStartIncluding": "6.3.10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1FB20250-D599-4124-9B31-4ACBD815386B", "versionEndExcluding": "6.6.144", "versionStartIncluding": "6.4.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4E206B86-E0E3-4394-A93F-39F2D50A8AA8", "versionEndExcluding": "6.12.95", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E08ACB05-518A-4D61-A6C4-268D1BB6BF46", "versionEndExcluding": "6.18.37", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6241DF06-E6F3-4B61-B5A2-A60F2AE5B982", "versionEndExcluding": "7.0.14", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C18FAA06-B61A-4036-A12D-F06F5135E64B", "versionEndExcluding": "7.1.2", "versionStartIncluding": "7.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.4:-:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DE0B0BF6-0EEF-4FAD-927D-7A0DD77BEE75"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}