{"id":"CVE-2026-64387","state":"PUBLISHED","title":"smb: client: fix query directory replay double-free","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix query directory replay double-free\n\nA response-bearing attempt can return a replayable error and free its\nresponse buffer. If SMB2_query_directory_init() fails before the next send,\ncleanup retains the previous buffer type and frees that response again.\n\nReset response bookkeeping before each attempt to prevent the stale free.","publishedAt":"2026-07-25T08:50:35.543Z","updatedAt":"2026-10-19T20:38:26.713Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"433042a91f9373241307725b52de573933ffedbf","status":"affected","lessThan":"3409aedf3c81a810243da94164f6621c9d205c98","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"1665f25b1dea30bf2d02e16245d203a944c9d994","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"00b0fa425941438b664950a8ee65dfba2def4336","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"3317a5d015fca976475aa71df224056777316fde","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"9647492b5e41954be59d5157eddbcd4cdc1656f7","versionType":"git"},{"version":"6.6.32","status":"affected","lessThan":"6.6.145","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/smb2pdu.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.8","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/smb2pdu.c"]}],"references":["https://git.kernel.org/stable/c/3409aedf3c81a810243da94164f6621c9d205c98","https://git.kernel.org/stable/c/1665f25b1dea30bf2d02e16245d203a944c9d994","https://git.kernel.org/stable/c/00b0fa425941438b664950a8ee65dfba2def4336","https://git.kernel.org/stable/c/3317a5d015fca976475aa71df224056777316fde","https://git.kernel.org/stable/c/9647492b5e41954be59d5157eddbcd4cdc1656f7"],"weaknesses":["CWE-415"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64387.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64387","state":"PUBLISHED","datePublished":"2026-07-25T08:50:35.543Z","dateUpdated":"2026-10-19T20:38:26.713Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.784Z"},"containers":{"cna":{"title":"smb: client: fix query directory replay double-free","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix query directory replay double-free\n\nA response-bearing attempt can return a replayable error and free its\nresponse buffer. If SMB2_query_directory_init() fails before the next send,\ncleanup retains the previous buffer type and frees that response again.\n\nReset response bookkeeping before each attempt to prevent the stale free."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"433042a91f9373241307725b52de573933ffedbf","status":"affected","lessThan":"3409aedf3c81a810243da94164f6621c9d205c98","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"1665f25b1dea30bf2d02e16245d203a944c9d994","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"00b0fa425941438b664950a8ee65dfba2def4336","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"3317a5d015fca976475aa71df224056777316fde","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"9647492b5e41954be59d5157eddbcd4cdc1656f7","versionType":"git"},{"version":"6.6.32","status":"affected","lessThan":"6.6.145","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/smb2pdu.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.8","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/smb2pdu.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/3409aedf3c81a810243da94164f6621c9d205c98"},{"url":"https://git.kernel.org/stable/c/1665f25b1dea30bf2d02e16245d203a944c9d994"},{"url":"https://git.kernel.org/stable/c/00b0fa425941438b664950a8ee65dfba2def4336"},{"url":"https://git.kernel.org/stable/c/3317a5d015fca976475aa71df224056777316fde"},{"url":"https://git.kernel.org/stable/c/9647492b5e41954be59d5157eddbcd4cdc1656f7"}],"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 - A malicious remote SMB server can trigger the flaw through crafted responses to SMB2 QUERY_DIRECTORY requests over the established network connection.\nAC:L - On a hard/retrans-enabled mount, the server controls the replayable error and can repeatedly induce disconnect/reconnect conditions before request reinitialization, without relying on an uncontrollable race.\nPR:N - The attacker needs no account or privilege on the client; the client authenticates to the attacker-controlled SMB server, and ordinary accessible-share enumeration reaches the code.\nUI:N - In a reasonable auto-mounted deployment, routine directory enumeration can be performed automatically by a daemon or application without human participation.\nS:U - The corruption occurs within the client kernel and compromises resources governed by that same kernel security authority.\nC:H - Double-freeing the attacker-influenced CIFS response object can poison the slab freelist or create overlapping allocations, providing UAF-style primitives capable of exposing arbitrary kernel memory.\nI:H - Allocator corruption and aliased CIFS buffers can enable attacker-influenced writes and potentially control-flow hijacking or kernel code execution.\nA:H - The double-free can immediately trigger allocator diagnostics, an oops, or a kernel panic, and corrupted freelists can cause subsequent fatal faults."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:54:39.446Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.32","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.12.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64387","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:40:04.387424Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-415","lang":"en","type":"CWE","description":"CWE-415 Double Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:38:26.713Z"}}]}}}