{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-31608", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.122Z", "datePublished": "2026-04-24T14:42:30.137Z", "dateUpdated": "2026-08-05T12:23:46.955Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:23:46.955Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list()\n\nsmb_direct_flush_send_list() already calls smb_direct_free_sendmsg(),\nso we should not call it again after post_sendmsg()\nmoved it to the batch list." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - SMB Direct in ksmbd is exposed over RDMA network listeners on SMB-related ports, and a remote RDMA-capable peer can reach the vulnerable send path. The affected subsystem is an in-kernel SMB server transport, so the defensible vector is Network.\nAC:L - The attacker can establish an SMB Direct connection, request immediate/credit responses, and induce send failure by controlling the peer connection state. Any timing involved is attacker-controlled and repeatable, so complexity is Low.\nPR:N - The vulnerable path is reachable after RDMA/SMB Direct transport negotiation and before SMB user authentication. No valid SMB session or credentials are required to trigger the lower transport credit/keepalive send path.\nUI:N - Exploitation only requires network interaction with the listening ksmbd SMB Direct service. No victim user action is needed.\nS:U - The corruption occurs within the kernel handling the ksmbd transport and impacts the same kernel security authority. This is not a VM escape, sandbox boundary crossing, or separate security scope.\nC:H - The bug is a kernel heap double-free of an SMB Direct send object, which can create use-after-free or overlapping-allocation conditions. Such memory corruption can reasonably be leveraged for kernel memory disclosure, so Confidentiality is High.\nI:H - A double-free in kernel heap/mempool state can be exploitable for controlled memory corruption and potentially control-flow or data modification. Following the higher-severity rule for memory corruption, Integrity is High.\nA:H - At minimum, the double-free can corrupt allocator state or trigger kernel warnings/oops/panic during send teardown. A remote unauthenticated peer can repeatedly trigger the condition, so Availability is High." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/transport_rdma.c" ], "versions": [ { "version": "5ef18a2e66f2f33fdac64437bddfb9fe6389fdc7", "lessThan": "6968c91fab05b8fc4d6700e0cf34472bb422df25", "status": "affected", "versionType": "git" }, { "version": "79242e7b6bc63efec28b7c235bc320806afce6c0", "lessThan": "2ba03f46132b0d1a7bafb86e1ef61951a2254023", "status": "affected", "versionType": "git" }, { "version": "34abd408c8ba24d7c97bd02ba874d8c714f49db1", "lessThan": "830de6eeb9db4cb7e758201fb99328ef4ca4b032", "status": "affected", "versionType": "git" }, { "version": "34abd408c8ba24d7c97bd02ba874d8c714f49db1", "lessThan": "84ff995ae826aa6bbcc6c7b9ea569ff67c021d72", "status": "affected", "versionType": "git" }, { "version": "6.18.11", "lessThan": "6.18.24", "status": "affected", "versionType": "semver" }, { "version": "6.19.1", "lessThan": "6.19.14", "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/transport_rdma.c" ], "versions": [ { "version": "7.0", "status": "affected" }, { "version": "0", "lessThan": "7.0", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.24", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.14", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.1", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "6.18.11", "versionEndExcluding": "6.18.24" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19.1", "versionEndExcluding": "6.19.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.0.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6968c91fab05b8fc4d6700e0cf34472bb422df25" }, { "url": "https://git.kernel.org/stable/c/2ba03f46132b0d1a7bafb86e1ef61951a2254023" }, { "url": "https://git.kernel.org/stable/c/830de6eeb9db4cb7e758201fb99328ef4ca4b032" }, { "url": "https://git.kernel.org/stable/c/84ff995ae826aa6bbcc6c7b9ea569ff67c021d72" } ], "title": "smb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list()", "x_generator": { "engine": "bippy-1.2.0" } } } }