{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74522", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.911Z", "datePublished": "2026-08-15T12:27:39.945Z", "dateUpdated": "2026-08-19T16:38:25.036Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:38:25.036Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free in __close_file_table_ids()\n\nA ksmbd_file can remain alive after logical close while another session\nholds a temporary reference obtained through ksmbd_lookup_fd_inode().\nksmbd_close_fd() currently marks the file closed and drops the idr-owned\nreference, but leaves the pointer published in the closing session's idr\nuntil the final reference is dropped.\n\nIf the foreign holder performs the final ksmbd_fd_put(), __put_fd_final()\nsupplies the foreign session's file table to __ksmbd_close_fd(). The object\nis then freed without being removed from its owner's idr, and the owner\nsession later dereferences the stale pointer during file-table teardown.\n\nRemove the volatile id from the owner's idr while ksmbd_close_fd() still\nholds that table's lock, and clear volatile_id before dropping\nthe idr-owned reference. A later foreign final put then only performs\nphysical destruction and cannot remove the object from the wrong table." } ], "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 bug is in ksmbd, the in-kernel SMB server reached remotely over TCP port 445 via SMB2 CREATE/CLOSE/SET_INFO rename and session teardown requests.\nAC:L - An attacker controls both sides of the race by issuing concurrent SMB2 CLOSE and rename operations on the same share, then logoff or disconnect; no victim-dependent timing or memory layout is required.\nPR:L - Exploitation requires a valid authenticated SMB session and share access to open, close, and rename files; it is not reachable on pre-authentication negotiate/echo paths.\nUI:N - No end-user action is required beyond the attacker driving SMB protocol operations on their own client connection(s).\nS:U - Impact is confined to kernel memory corruption and privilege escalation on the SMB server host; it does not cross a VM, container, or IOMMU security boundary.\nC:H - Use-after-free of a freed ksmbd_file slab object during session file-table teardown enables reading attacker-influenced heap contents and building arbitrary kernel memory read primitives.\nI:H - The UAF corrupts kernel heap metadata and ksmbd_file fields (pointers, list heads), enabling heap grooming and arbitrary write or control-flow hijack for code execution as root.\nA:H - The stale IDR entry is dereferenced during __close_file_table_ids() on logoff, tree disconnect, or connection teardown, causing kernel oops/panic and repeatable remote 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/vfs_cache.c" ], "versions": [ { "version": "8510a043d334ecdf83d4604782f288db6bf21d60", "lessThan": "19bfd90d5aaf63217735d81964585c5306158e5f", "status": "affected", "versionType": "git" }, { "version": "8510a043d334ecdf83d4604782f288db6bf21d60", "lessThan": "67aaec2a1fdce3e1dde46c45b5d1ef8cf22f65cd", "status": "affected", "versionType": "git" }, { "version": "8510a043d334ecdf83d4604782f288db6bf21d60", "lessThan": "0c3918c2cee62ec6c9de8d5c73ebfe6f833961ac", "status": "affected", "versionType": "git" }, { "version": "8510a043d334ecdf83d4604782f288db6bf21d60", "lessThan": "9be4a66f019ea90bd9deca70511f4f9ffebf5c6f", "status": "affected", "versionType": "git" }, { "version": "8510a043d334ecdf83d4604782f288db6bf21d60", "lessThan": "cffbdc86393b0235383a20c8c59bc32f16036459", "status": "affected", "versionType": "git" }, { "version": "8510a043d334ecdf83d4604782f288db6bf21d60", "lessThan": "e7188199eff46a636f3436356f0aae039be6dd66", "status": "affected", "versionType": "git" }, { "version": "df30cbfd3d8a70e61ce59f63ce5ed2261799ac10", "status": "affected", "versionType": "git" }, { "version": "aaf1d5ebb358f546414965b39da90107a7ca7ce5", "status": "affected", "versionType": "git" }, { "version": "5.15.38", "lessThan": "5.16", "status": "affected", "versionType": "semver" }, { "version": "5.17.6", "lessThan": "5.18", "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/vfs_cache.c" ], "versions": [ { "version": "5.18", "status": "affected" }, { "version": "0", "lessThan": "5.18", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.151", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.8", "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": "5.18", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.6.151" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.12.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.18.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.1.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.38" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17.6" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/19bfd90d5aaf63217735d81964585c5306158e5f" }, { "url": "https://git.kernel.org/stable/c/67aaec2a1fdce3e1dde46c45b5d1ef8cf22f65cd" }, { "url": "https://git.kernel.org/stable/c/0c3918c2cee62ec6c9de8d5c73ebfe6f833961ac" }, { "url": "https://git.kernel.org/stable/c/9be4a66f019ea90bd9deca70511f4f9ffebf5c6f" }, { "url": "https://git.kernel.org/stable/c/cffbdc86393b0235383a20c8c59bc32f16036459" }, { "url": "https://git.kernel.org/stable/c/e7188199eff46a636f3436356f0aae039be6dd66" } ], "title": "ksmbd: fix use-after-free in __close_file_table_ids()", "x_generator": { "engine": "bippy-1.2.0" } } } }