CVE-2026-89536

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89536", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.721Z", "datePublished": "2026-09-11T19:44:14.473Z", "dateUpdated": "2026-10-19T08:48:28.030Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:48:28.030Z"}, "descriptions": [{"lang": "en", "value": "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 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."}], "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 bug is in the SUNRPC TCP-with-TLS client handshake (xs_tls_handshake_sync), reached when a remote NFS/RPC peer completes RPC-with-TLS; a malicious server or on-path attacker with xprtsec=tls (anonymous TLS) drives handshake_complete() over the network against the client's 10s wait.\nAC:L - The attacker times TLS completion against the fixed XS_TLS_HANDSHAKE_TO window and can force repeated reconnects so tls_handshake_cancel() losing to handshake_complete() is reliably hittable, with no memory-layout guess or other condition outside attacker control.\nPR:N - No privileges on the victim host are required; a remote TLS peer only needs the client to initiate or re-establish an RPC-with-TLS connection, and the handshake runs after AUTH_TLS STARTTLS but before NFS credentials are verified.\nUI:N - No victim action is needed at attack time once an NFS xprtsec=tls/mtls mount exists, because idle disconnect or server-induced reconnect automatically re-enters xs_tcp_tls_setup_socket() and the handshake wait.\nS:U - The use-after-free corrupts kernel heap state in the SUNRPC client on the same host; impact stays within that kernel's security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - When cancel loses, the waiter still xprt_put()s the callback-owned rpc_xprt reference, so sock_xprt can be freed while xs_tls_handshake_done() writes xprt_err and the connect worker still uses lower_xprt, a heap UAF enabling arbitrary disclosure.\nI:H - Use-after-free of rpc_xprt/sock_xprt (ops pointers, wait queues, socket state) allows heap reuse for arbitrary writes and control-flow hijacking, not merely a crash.\nA:H - The extra put can destroy the transport while the handshake waiter and connect worker still touch it, producing a kernel oops/panic or a hang in xprt_destroy waiting on XPRT_LOCKED, denying NFS/RPC service."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/sunrpc/xprtsock.c"], "versions": [{"version": "75eb6af7acdf566c68d61e98e67ee2f235201c02", "lessThan": "fb43997407bc17ee39bac81ab708101312e255f5", "status": "affected", "versionType": "git"}, {"version": "75eb6af7acdf566c68d61e98e67ee2f235201c02", "lessThan": "15431820f448e09f8029b670d5c82aa5917d4625", "status": "affected", "versionType": "git"}, {"version": "75eb6af7acdf566c68d61e98e67ee2f235201c02", "lessThan": "1de391e8b94e31b45c19c16dbf315e294810c7de", "status": "affected", "versionType": "git"}, {"version": "75eb6af7acdf566c68d61e98e67ee2f235201c02", "lessThan": "7fbb6d2ab0391eb8d1f1a68e6bc263ef02cea61b", "status": "affected", "versionType": "git"}, {"version": "75eb6af7acdf566c68d61e98e67ee2f235201c02", "lessThan": "a89dd597458848b463d284b15e42a8078beeb046", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/sunrpc/xprtsock.c"], "versions": [{"version": "6.5", "status": "affected"}, {"version": "0", "lessThan": "6.5", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "6.5", "versionEndExcluding": "6.6.157"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "6.12.109"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "7.3"}]}]}], "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"}], "title": "SUNRPC: wait for in-flight client TLS handshake callback", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/sunrpc/xprtsock.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "fb43997407bc17ee39bac81ab708101312e255f5", "status": "affected", "version": "75eb6af7acdf566c68d61e98e67ee2f235201c02", "versionType": "git"}, {"lessThan": "15431820f448e09f8029b670d5c82aa5917d4625", "status": "affected", "version": "75eb6af7acdf566c68d61e98e67ee2f235201c02", "versionType": "git"}, {"lessThan": "1de391e8b94e31b45c19c16dbf315e294810c7de", "status": "affected", "version": "75eb6af7acdf566c68d61e98e67ee2f235201c02", "versionType": "git"}, {"lessThan": "7fbb6d2ab0391eb8d1f1a68e6bc263ef02cea61b", "status": "affected", "version": "75eb6af7acdf566c68d61e98e67ee2f235201c02", "versionType": "git"}, {"lessThan": "a89dd597458848b463d284b15e42a8078beeb046", "status": "affected", "version": "75eb6af7acdf566c68d61e98e67ee2f235201c02", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/sunrpc/xprtsock.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.5"}, {"lessThan": "6.5", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.157", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.109", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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 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."}], "id": "CVE-2026-89536", "lastModified": "2026-10-19T09:17:48.317", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-11T20:19:36.613", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/15431820f448e09f8029b670d5c82aa5917d4625"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1de391e8b94e31b45c19c16dbf315e294810c7de"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7fbb6d2ab0391eb8d1f1a68e6bc263ef02cea61b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a89dd597458848b463d284b15e42a8078beeb046"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fb43997407bc17ee39bac81ab708101312e255f5"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel: Memory corruption in SUNRPC client TLS handshake", "id": "2532264", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532264"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.3", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-911", "details": ["A flaw was found in the Linux kernel's SUNRPC (Sun Remote Procedure Call) client TLS (Transport Layer Security) handshake process. A race condition exists where a reference to the lower transport can be prematurely released during handshake cancellation. This can lead to memory corruption, potentially allowing an attacker to cause a denial of service."], "name": "CVE-2026-89536", "public_date": "2026-09-11T19:44:14Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89536\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89536\nhttps://git.kernel.org/stable/c/15431820f448e09f8029b670d5c82aa5917d4625\nhttps://git.kernel.org/stable/c/1de391e8b94e31b45c19c16dbf315e294810c7de\nhttps://git.kernel.org/stable/c/7fbb6d2ab0391eb8d1f1a68e6bc263ef02cea61b\nhttps://git.kernel.org/stable/c/a89dd597458848b463d284b15e42a8078beeb046"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[75eb6af7acdf566c68d61e98e67ee2f235201c02,15431820f448e09f8029b670d5c82aa5917d4625)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[75eb6af7acdf566c68d61e98e67ee2f235201c02,1de391e8b94e31b45c19c16dbf315e294810c7de)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[75eb6af7acdf566c68d61e98e67ee2f235201c02,7fbb6d2ab0391eb8d1f1a68e6bc263ef02cea61b)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[75eb6af7acdf566c68d61e98e67ee2f235201c02,a89dd597458848b463d284b15e42a8078beeb046)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.5"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.5)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.109,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.50,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.4,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-12T03:30:08.482595+00:00", "updated": "2026-09-15T22:15:17.695513+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}