{"id":"CVE-2026-64383","state":"PUBLISHED","title":"smb: client: fix double-free in SMB2_flush() replay","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix double-free in SMB2_flush() replay\n\nSMB2_flush() keeps its response buffer bookkeeping across replay\nattempts. If a replayable flush response is received and the retry then\nfails before cifs_send_recv() stores a replacement response, flush_exit\nwill free the stale response pointer a second time.\n\nReinitialize resp_buftype and rsp_iov at the top of the replay loop so\ncleanup only acts on response state produced by the current attempt.\nThis fixes a double-free without changing replay handling for successful\nrequests.","publishedAt":"2026-07-25T08:50:32.634Z","updatedAt":"2026-10-19T20:38:26.139Z","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":"6e27f40b682a5e42a2daae3ce6d96f0e0e16dedb","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"878757163eea684750107a31ea134c103863515d","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"3407240cde132a4b72d6429a2625a09a2f78adaf","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"013a9a3da46c5dabcf18f65ea6a47874ba12a15d","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"4be31c943a3a27a5a0251dbb8f5cb89059ec3d5a","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/6e27f40b682a5e42a2daae3ce6d96f0e0e16dedb","https://git.kernel.org/stable/c/878757163eea684750107a31ea134c103863515d","https://git.kernel.org/stable/c/3407240cde132a4b72d6429a2625a09a2f78adaf","https://git.kernel.org/stable/c/013a9a3da46c5dabcf18f65ea6a47874ba12a15d","https://git.kernel.org/stable/c/4be31c943a3a27a5a0251dbb8f5cb89059ec3d5a"],"weaknesses":["CWE-415"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64383.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64383","state":"PUBLISHED","datePublished":"2026-07-25T08:50:32.634Z","dateUpdated":"2026-10-19T20:38:26.139Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.784Z"},"containers":{"cna":{"title":"smb: client: fix double-free in SMB2_flush() replay","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix double-free in SMB2_flush() replay\n\nSMB2_flush() keeps its response buffer bookkeeping across replay\nattempts. If a replayable flush response is received and the retry then\nfails before cifs_send_recv() stores a replacement response, flush_exit\nwill free the stale response pointer a second time.\n\nReinitialize resp_buftype and rsp_iov at the top of the replay loop so\ncleanup only acts on response state produced by the current attempt.\nThis fixes a double-free without changing replay handling for successful\nrequests."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"433042a91f9373241307725b52de573933ffedbf","status":"affected","lessThan":"6e27f40b682a5e42a2daae3ce6d96f0e0e16dedb","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"878757163eea684750107a31ea134c103863515d","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"3407240cde132a4b72d6429a2625a09a2f78adaf","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"013a9a3da46c5dabcf18f65ea6a47874ba12a15d","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"4be31c943a3a27a5a0251dbb8f5cb89059ec3d5a","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/6e27f40b682a5e42a2daae3ce6d96f0e0e16dedb"},{"url":"https://git.kernel.org/stable/c/878757163eea684750107a31ea134c103863515d"},{"url":"https://git.kernel.org/stable/c/3407240cde132a4b72d6429a2625a09a2f78adaf"},{"url":"https://git.kernel.org/stable/c/013a9a3da46c5dabcf18f65ea6a47874ba12a15d"},{"url":"https://git.kernel.org/stable/c/4be31c943a3a27a5a0251dbb8f5cb89059ec3d5a"}],"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 or compromised SMB server can trigger the flaw through crafted replayable responses and connection failures over the network.\nAC:L - The server controls both the replayable error and subsequent reconnect failure, allowing repeated triggering without an uncontrollable race.\nPR:N - The attacking SMB endpoint requires no privileges on the client system once an SMB session and file handle exist.\nUI:N - An automatically mounted share and routine service-generated fsync, truncate, timestamp, or seek operations can reach SMB2_flush() without human participation.\nS:U - The memory corruption compromises resources governed by the same host kernel security authority.\nC:H - The response-buffer double-free can create overlapping CIFS slab allocations and use-after-free primitives capable of exposing arbitrary kernel memory.\nI:H - Allocator corruption and attacker-influenced overlapping network buffers can provide arbitrary-write or control-flow-hijacking primitives.\nA:H - The double-free can immediately trigger an allocator BUG, kernel oops, or panic and can be invoked repeatedly."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:54:35.045Z"},"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-2026-64383","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:39:52.688233Z"}}}],"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":"2026-10-19T20:38:26.139Z"}}]}}}