{"id":"CVE-2026-64535","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-64535","generatedAt":"2026-10-28T03:27:24.037Z","title":"In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: Fix potential UAF when ddgst mismatch Shivam Kumar found via vulnerability testing: When data digest is enabled on an NVMe/TCP connection and a digest mismatch occurs on a…","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.","published":"2026-07-27T08:16:23.000Z","lastModified":"2026-10-19T21:17:43.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","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"},"cwe":["CWE-415"],"affected":[],"epss":{"score":0.00547,"percentile":0.45603,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.55%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/088ee46c18d99baef453afd74181dd40ade044ad","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6f9442983a3e4227afd1c83a5251ddbca585ea21","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7e558308eba14c8136cb1e615f0c850f76d1fc0a","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/96fe2513df590e74b04253a45089cae75569570e","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dbbd07d0a7020b80f6a7028e561908f7b83b3d5a","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dfb902462bca478f050224ec7a7195aafa7643b1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e091ff83d962f9ed00d9bd70443676de9fe98bdc","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64535","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}