{"api_version":"1","generated_at":"2026-08-02T09:03:46+00:00","cve":"CVE-2026-64535","urls":{"html":"https://cve.report/CVE-2026-64535","api":"https://cve.report/api/cve/CVE-2026-64535.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64535","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64535"},"summary":{"title":"nvmet-tcp: Fix potential UAF when ddgst mismatch","description":"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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-27 08:16:22","updated_at":"2026-07-30 06:25:57"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"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","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/96fe2513df590e74b04253a45089cae75569570e","name":"https://git.kernel.org/stable/c/96fe2513df590e74b04253a45089cae75569570e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/088ee46c18d99baef453afd74181dd40ade044ad","name":"https://git.kernel.org/stable/c/088ee46c18d99baef453afd74181dd40ade044ad","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6f9442983a3e4227afd1c83a5251ddbca585ea21","name":"https://git.kernel.org/stable/c/6f9442983a3e4227afd1c83a5251ddbca585ea21","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dbbd07d0a7020b80f6a7028e561908f7b83b3d5a","name":"https://git.kernel.org/stable/c/dbbd07d0a7020b80f6a7028e561908f7b83b3d5a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e091ff83d962f9ed00d9bd70443676de9fe98bdc","name":"https://git.kernel.org/stable/c/e091ff83d962f9ed00d9bd70443676de9fe98bdc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64535","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64535","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 96fe2513df590e74b04253a45089cae75569570e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 e091ff83d962f9ed00d9bd70443676de9fe98bdc git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 6f9442983a3e4227afd1c83a5251ddbca585ea21 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 088ee46c18d99baef453afd74181dd40ade044ad git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 dbbd07d0a7020b80f6a7028e561908f7b83b3d5a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.1.178 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.6.145 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.12.97 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.18.40 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.178 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.97 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"64535","cve":"CVE-2026-64535","epss":"0.004730000","percentile":"0.384170000","score_date":"2026-08-01","updated_at":"2026-08-02 00:11:14"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/nvme/target/tcp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"96fe2513df590e74b04253a45089cae75569570e","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"e091ff83d962f9ed00d9bd70443676de9fe98bdc","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"6f9442983a3e4227afd1c83a5251ddbca585ea21","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"088ee46c18d99baef453afd74181dd40ade044ad","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"dbbd07d0a7020b80f6a7028e561908f7b83b3d5a","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"6.1.178","status":"affected","version":"0","versionType":"semver"},{"lessThan":"6.6.145","status":"affected","version":"0","versionType":"semver"},{"lessThan":"6.12.97","status":"affected","version":"0","versionType":"semver"},{"lessThan":"6.18.40","status":"affected","version":"0","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/nvme/target/tcp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.178","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.97","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.40","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.178","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.97","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.40","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-30T06:06:31.160Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"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"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64535","datePublished":"2026-07-27T06:32:34.859Z","dateReserved":"2026-07-19T15:36:31.795Z","dateUpdated":"2026-07-30T06:06:31.160Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-27 08:16:22","lastModifiedDate":"2026-07-30 06:25:57","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"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","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64535","Ordinal":"1","Title":"nvmet-tcp: Fix potential UAF when ddgst mismatch","CVE":"CVE-2026-64535","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64535","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"nvmet-tcp: Fix potential UAF when ddgst mismatch"}]}}}