{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64535", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.795Z", "datePublished": "2026-07-27T06:32:34.859Z", "dateUpdated": "2026-10-19T20:48:39.004Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:28:23.449Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet-tcp: Fix potential UAF when ddgst mismatch\n\nShivam Kumar found via vulnerability testing:\nWhen data digest is enabled on an NVMe/TCP connection and a digest\nmismatch occurs on a non-final H2C_DATA PDU during an R2T-based\ndata transfer, the digest error handler in nvmet_tcp_try_recv_ddgst()\ncalls nvmet_req_uninit() — which performs percpu_ref_put() on the\nsubmission queue — but does NOT mark the command as completed. It\ndoes not set cqe->status, does not modify rbytes_done, and does not\nclear any flag. When the subsequent fatal error triggers queue\nteardown, nvmet_tcp_uninit_data_in_cmds() iterates all commands,\nchecks nvmet_tcp_need_data_in() for each one, and finds that the\nalready-uninited command still appears to need data (because\nrbytes_done < transfer_len and cqe->status == 0). It therefore calls\nnvmet_req_uninit() a second time on the same command — a double\npercpu_ref_put against a single percpu_ref_get." } ], "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 - The vulnerable NVMe/TCP target receive worker processes attacker-controlled H2C_DATA PDUs received through a listening TCP socket, making it remotely network reachable.\nAC:L - The attacker controls digest negotiation, PDU chunking, transfer length, and digest contents, allowing a non-final digest mismatch to be triggered deterministically while keeping other I/O outstanding.\nPR:N - A reasonable non-TLS target deployment using allow_any_host requires no credentials or local capabilities; the remote peer can negotiate data digests and submit the malicious protocol sequence directly.\nUI:N - Exploitation requires only network protocol traffic and no action by a victim user.\nS:U - The vulnerable receive processing and resulting kernel compromise occur within the target host's existing kernel security authority.\nC:H - The premature reference release can free queue, request, response-buffer, and percpu-ref state while asynchronous completions still access it, creating a kernel UAF capable of arbitrary memory disclosure.\nI:H - The kernel UAF exposes writes through reclaimed request and queue structures and is plausibly exploitable for arbitrary kernel memory modification or code execution.\nA:H - The refcount corruption can cause a permanent workqueue teardown deadlock, while the resulting UAF can also produce an oops or kernel panic; the network trigger can be repeated." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/nvme/target/tcp.c" ], "versions": [ { "version": "91edfca6f8b364d60cde3ddefaf7d03ddf35774b", "lessThan": "dfb902462bca478f050224ec7a7195aafa7643b1", "status": "affected", "versionType": "git" }, { "version": "fda871c0ba5d2eed2cd1c881573168129da70058", "lessThan": "7e558308eba14c8136cb1e615f0c850f76d1fc0a", "status": "affected", "versionType": "git" }, { "version": "fda871c0ba5d2eed2cd1c881573168129da70058", "lessThan": "96fe2513df590e74b04253a45089cae75569570e", "status": "affected", "versionType": "git" }, { "version": "fda871c0ba5d2eed2cd1c881573168129da70058", "lessThan": "e091ff83d962f9ed00d9bd70443676de9fe98bdc", "status": "affected", "versionType": "git" }, { "version": "fda871c0ba5d2eed2cd1c881573168129da70058", "lessThan": "6f9442983a3e4227afd1c83a5251ddbca585ea21", "status": "affected", "versionType": "git" }, { "version": "fda871c0ba5d2eed2cd1c881573168129da70058", "lessThan": "088ee46c18d99baef453afd74181dd40ade044ad", "status": "affected", "versionType": "git" }, { "version": "fda871c0ba5d2eed2cd1c881573168129da70058", "lessThan": "dbbd07d0a7020b80f6a7028e561908f7b83b3d5a", "status": "affected", "versionType": "git" }, { "version": "4b17476d809273617d3317fa0d4ae78aa488d760", "status": "affected", "versionType": "git" }, { "version": "5.10.20", "lessThan": "5.10.265", "status": "affected", "versionType": "semver" }, { "version": "5.11.3", "lessThan": "5.12", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/nvme/target/tcp.c" ], "versions": [ { "version": "5.12", "status": "affected" }, { "version": "0", "lessThan": "5.12", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "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": "5.10.20", "versionEndExcluding": "5.10.265" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "5.15.216" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "7.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/dfb902462bca478f050224ec7a7195aafa7643b1" }, { "url": "https://git.kernel.org/stable/c/7e558308eba14c8136cb1e615f0c850f76d1fc0a" }, { "url": "https://git.kernel.org/stable/c/96fe2513df590e74b04253a45089cae75569570e" }, { "url": "https://git.kernel.org/stable/c/e091ff83d962f9ed00d9bd70443676de9fe98bdc" }, { "url": "https://git.kernel.org/stable/c/6f9442983a3e4227afd1c83a5251ddbca585ea21" }, { "url": "https://git.kernel.org/stable/c/088ee46c18d99baef453afd74181dd40ade044ad" }, { "url": "https://git.kernel.org/stable/c/dbbd07d0a7020b80f6a7028e561908f7b83b3d5a" } ], "title": "nvmet-tcp: Fix potential UAF when ddgst mismatch", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-64535", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T15:41:56.047833Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-415", "description": "CWE-415 Double Free" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-19T20:48:39.004Z" } } ] } }