{"id":"CVE-2026-89536","title":"SUNRPC: wait for in-flight client TLS handshake callback","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: wait for in-flight client TLS handshake callback\n\nxs_tls_handshake_sync() gives xs_tls_handshake_done() a reference to the\nlower transport before submitting the…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 75eb6af7acdf566c68d61e98e67ee2f235201c02 < fb43997407bc17ee39bac81ab708101312e255f5","Linux >= 75eb6af7acdf566c68d61e98e67ee2f235201c02 < 15431820f448e09f8029b670d5c82aa5917d4625","Linux >= 75eb6af7acdf566c68d61e98e67ee2f235201c02 < 1de391e8b94e31b45c19c16dbf315e294810c7de","Linux >= 75eb6af7acdf566c68d61e98e67ee2f235201c02 < 7fbb6d2ab0391eb8d1f1a68e6bc263ef02cea61b","Linux >= 75eb6af7acdf566c68d61e98e67ee2f235201c02 < a89dd597458848b463d284b15e42a8078beeb046","Linux 6.5"],"published":"2026-09-11","updated":"2026-09-14","sourceUpdated":"2026-09-14T12:00:45.076Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89536","references":[{"url":"https://git.kernel.org/stable/c/fb43997407bc17ee39bac81ab708101312e255f5"},{"url":"https://git.kernel.org/stable/c/15431820f448e09f8029b670d5c82aa5917d4625"},{"url":"https://git.kernel.org/stable/c/1de391e8b94e31b45c19c16dbf315e294810c7de"},{"url":"https://git.kernel.org/stable/c/7fbb6d2ab0391eb8d1f1a68e6bc263ef02cea61b"},{"url":"https://git.kernel.org/stable/c/a89dd597458848b463d284b15e42a8078beeb046"}],"tags":["cve.org"],"epss":0.00626,"epssPercentile":0.4867,"ingestedAt":"2026-09-14T15:23:07.452Z","slug":"CVE-2026-89536","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: wait for in-flight client TLS handshake callback\n\nxs_tls_handshake_sync() gives xs_tls_handshake_done() a reference to the\nlower transport before submitting the handshake request. On timeout or\nsignal, the synchronous waiter drops that reference after calling\ntls_handshake_cancel().\n\nhandshake_req_cancel() returns false when handshake_complete() has\nalready marked the request complete. In that case the completion callback\ncan still be running, so dropping the callback-owned reference in the\nwaiter can free the lower transport before xs_tls_handshake_done() stores\nxprt_err or drops its own reference.\n\nIf cancellation loses to completion, wait until xs_tls_handshake_done()\nsignals handshake_done and let the callback release its reference. This\nmirrors the server-side handshake lifetime handling and keeps the timeout\nor signal return value unchanged.\n\n## Affected\n\n- `Linux >= 75eb6af7acdf566c68d61e98e67ee2f235201c02 < fb43997407bc17ee39bac81ab708101312e255f5`\n- `Linux >= 75eb6af7acdf566c68d61e98e67ee2f235201c02 < 15431820f448e09f8029b670d5c82aa5917d4625`\n- `Linux >= 75eb6af7acdf566c68d61e98e67ee2f235201c02 < 1de391e8b94e31b45c19c16dbf315e294810c7de`\n- `Linux >= 75eb6af7acdf566c68d61e98e67ee2f235201c02 < 7fbb6d2ab0391eb8d1f1a68e6bc263ef02cea61b`\n- `Linux >= 75eb6af7acdf566c68d61e98e67ee2f235201c02 < a89dd597458848b463d284b15e42a8078beeb046`\n- `Linux 6.5`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":197955,"id":"CVE-2026-89536","ts":1789384321129,"field":"cvss","old":"5.3","new":"9.8"},{"seq":197954,"id":"CVE-2026-89536","ts":1789384321129,"field":"severity","old":"medium","new":"critical"},{"seq":183494,"id":"CVE-2026-89536","ts":1789356675600,"field":"cvss","old":"9.8","new":"5.3"},{"seq":183493,"id":"CVE-2026-89536","ts":1789356675600,"field":"severity","old":"critical","new":"medium"},{"seq":153332,"id":"CVE-2026-89536","ts":1789285350081,"field":"cvss","old":null,"new":"9.8"},{"seq":153331,"id":"CVE-2026-89536","ts":1789285350081,"field":"severity","old":"none","new":"critical"},{"seq":147450,"id":"CVE-2026-89536","ts":1789270210956,"field":"cvss","old":null,"new":"5.3"},{"seq":147449,"id":"CVE-2026-89536","ts":1789270210956,"field":"severity","old":"none","new":"medium"},{"seq":109208,"id":"CVE-2026-89536","ts":1789183730732,"field":"cvss","old":null,"new":"5.3"},{"seq":109207,"id":"CVE-2026-89536","ts":1789183730732,"field":"severity","old":"none","new":"medium"}]}