{"id":"CVE-2026-64597","state":"PUBLISHED","title":"smb: client: fix double-free in SMB2_close() replay","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix double-free in SMB2_close() replay\n\nA response-bearing attempt can return a replayable error and free its\nresponse buffer. If SMB2_close_init() fails before the next send, cleanup\nretains the previous buffer type and frees that response again.\n\nReset response bookkeeping before each attempt to prevent the stale free.","publishedAt":"2026-08-06T07:13:52.117Z","updatedAt":"2026-10-19T20:48:43.468Z","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":"037511726228aaf165c7067ff2bfc88eaecdf1f3","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"0aa97edf7c347c0f54e7e60c4740574b8120c66a","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"d15d83125007f673aec4323e1bbbaaffbe87ea13","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"b18ed621dbfceecea5539848cddcb9272c9a61e1","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"f96e1cdcb63ed3321142ff2fcdf784e32cda8fee","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/037511726228aaf165c7067ff2bfc88eaecdf1f3","https://git.kernel.org/stable/c/0aa97edf7c347c0f54e7e60c4740574b8120c66a","https://git.kernel.org/stable/c/d15d83125007f673aec4323e1bbbaaffbe87ea13","https://git.kernel.org/stable/c/b18ed621dbfceecea5539848cddcb9272c9a61e1","https://git.kernel.org/stable/c/f96e1cdcb63ed3321142ff2fcdf784e32cda8fee"],"weaknesses":["CWE-415"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64597.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64597","state":"PUBLISHED","datePublished":"2026-08-06T07:13:52.117Z","dateUpdated":"2026-10-19T20:48:43.468Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.799Z"},"containers":{"cna":{"title":"smb: client: fix double-free in SMB2_close() replay","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix double-free in SMB2_close() replay\n\nA response-bearing attempt can return a replayable error and free its\nresponse buffer. If SMB2_close_init() fails before the next send, cleanup\nretains 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":"037511726228aaf165c7067ff2bfc88eaecdf1f3","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"0aa97edf7c347c0f54e7e60c4740574b8120c66a","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"d15d83125007f673aec4323e1bbbaaffbe87ea13","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"b18ed621dbfceecea5539848cddcb9272c9a61e1","versionType":"git"},{"version":"4f1fffa2376922f3d1d506e49c0fd445b023a28e","status":"affected","lessThan":"f96e1cdcb63ed3321142ff2fcdf784e32cda8fee","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/037511726228aaf165c7067ff2bfc88eaecdf1f3"},{"url":"https://git.kernel.org/stable/c/0aa97edf7c347c0f54e7e60c4740574b8120c66a"},{"url":"https://git.kernel.org/stable/c/d15d83125007f673aec4323e1bbbaaffbe87ea13"},{"url":"https://git.kernel.org/stable/c/b18ed621dbfceecea5539848cddcb9272c9a61e1"},{"url":"https://git.kernel.org/stable/c/f96e1cdcb63ed3321142ff2fcdf784e32cda8fee"}],"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 triggers the double-free via crafted SMB2 CLOSE responses over the network, returning replayable NTSTATUS values that map to -EAGAIN/-ECONNABORTED while leaving a response buffer for the client to free.\nAC:L - The attacking server controls both sides of the sequence by returning a replayable CLOSE status with a response buffer, then dropping or forcing reconnect so SMB2_close_init fails before the next send, and can repeat until the stale free occurs.\nPR:N - The attacking SMB endpoint needs no account or privileges on the victim client; once an SMB session and handle exist, the server alone drives the vulnerable CLOSE replay path.\nUI:N - On an already mounted or automounted share, background paths such as cached-directory close and cancelled-close work, as well as routine service file closes, can invoke SMB2_close without interactive user action at exploit time.\nS:U - The mempool double-free corrupts kernel memory within the same host kernel security authority and does not inherently cross a VM, IOMMU, or sandbox boundary.\nC:H - Double-free of a CIFS small/large response buffer can create overlapping live allocations and use-after-free reads, enabling disclosure of arbitrary kernel memory.\nI:H - Reallocation of the freed mempool object with attacker-controlled network data can corrupt live kernel objects or allocator metadata, enabling arbitrary writes and control-flow hijacking.\nA:H - The duplicate free can immediately trigger allocator BUG diagnostics, heap corruption, oops, or panic, and the server can retrigger the path repeatedly."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:58:19.742Z"},"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-2026-64597","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:43:23.981933Z"}}}],"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":"2026-10-19T20:48:43.468Z"}}]}}}