{"id":"CVE-2026-80585","revision":null,"records":[{"revision":"a15f0a580a37431bad6cb586ef3ee73a","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-80585","aliases":[],"title":"mptcp: fastopen: only mark MPTFO subflows with SYN data","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fastopen: only mark MPTFO subflows with SYN data\n\nPassive TCP Fast Open accepts a valid-cookie SYN even when it carries\nno data. In that case the child socket's receive queue is intentionally\nleft empty.\n\nmptcp_fastopen_subflow_synack_set_params() set is_mptfo before checking\nfor queued SYN data. That made data-less TFO SYNs hit a WARN and, if\nthe warning was non-fatal, left stale MPTFO state behind. The stale\nflag could later trigger a state-confusion bug in\ncheck_fully_established().\n\nOnly mark the subflow as MPTFO after confirming that an SKB was queued.\nReturn quietly when the receive queue is empty.\n\nNote that mptcp_subflow_context's is_mptfo field is now not just about\nsubflows where the TFO was present, but about MPTFO subflow that\nconsumed SYN data. Only having a valid cookie but not carrying data is\nnot really \"doing TFO\".","state":0,"publishedAt":"2026-08-26T14:37:40.901+00:00","modifiedAt":"2026-10-16T19:26:28.485+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/mptcp/fastopen.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"36b122baf6a8bd46b4a591f12f4ed17b22257408\",\n                            \"lessThan\": \"f75f174edc865738522e514d042cf5627f084859\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"36b122baf6a8bd46b4a591f12f4ed17b22257408\",\n                            \"lessThan\": \"fca7e444c04689fe4cc6b56f2725f804a4bb1ef9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"36b122baf6a8bd46b4a591f12f4ed17b22257408\",\n                            \"lessThan\": \"75e564b2ced1cc3d9a8904c7d2d2bb448fffb8b5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"36b122baf6a8bd46b4a591f12f4ed17b22257408\",\n                            \"lessThan\": \"72b4a0c51a4b550d40301d60a366b429b8c8e78d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"36b122baf6a8bd46b4a591f12f4ed17b22257408\",\n                            \"lessThan\": \"e00b63056fb4f261455b3e5df5268a1f8ce47a87\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/mptcp/fastopen.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.2\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.2\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.153\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.105\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.46\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.10\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H","score":9.4,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/f75f174edc865738522e514d042cf5627f084859","https://git.kernel.org/stable/c/fca7e444c04689fe4cc6b56f2725f804a4bb1ef9","https://git.kernel.org/stable/c/75e564b2ced1cc3d9a8904c7d2d2bb448fffb8b5","https://git.kernel.org/stable/c/72b4a0c51a4b550d40301d60a366b429b8c8e78d","https://git.kernel.org/stable/c/e00b63056fb4f261455b3e5df5268a1f8ce47a87"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80585","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-80585","identifiers":["CVE-2026-80585"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-09T08:02:26.2193293+00:00","complete":true,"records":1769,"lastAttemptAt":"2026-11-09T08:02:26.2193293+00:00","lastSuccessAt":"2026-11-09T08:02:26.3903284+00:00","error":null,"lastVerifiedAt":"2026-11-09T08:02:26.3903314+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-24e6fde7b744113daefb8f6135035fb8a5c69c9617c9c0d40574a0376532ffd3-bac7baae6881807b2b4a9dce5cf5dd63af98be3e5c79f031b11fd288ebb8cee0","complete":true,"records":421301,"lastAttemptAt":"2026-11-09T08:02:25.6827821+00:00","lastSuccessAt":"2026-11-09T07:02:22.9878009+00:00","error":"HttpRequestException","lastVerifiedAt":"2026-11-09T07:02:23.0094052+00:00","snapshotPublishedAt":"2026-11-09T06:27:21+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-0bc6adcd3c0c448aa2e9bc2063d5a999","complete":false,"records":13654,"lastAttemptAt":"2026-11-09T08:14:22.8145543+00:00","lastSuccessAt":"2026-11-09T08:14:22.81+00:00","error":"14 identifier lookups failed; latest failures include HTTP 403. Other identifiers were checked independently.","lastVerifiedAt":"2026-11-09T08:14:22.81+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13684,"expectedIdentifiers":13706,"failedIdentifiers":14},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-09T08:02:26.2193293+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-09T08:02:26.2193293+00:00","lastSuccessAt":"2026-11-09T08:02:26.3910394+00:00","error":null,"lastVerifiedAt":"2026-11-09T08:02:26.3910397+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-156d67f0b09643159ff4bd684ee896db","complete":true,"records":13666,"lastAttemptAt":"2026-11-09T08:02:26.9587387+00:00","lastSuccessAt":"2026-11-09T07:04:26.209+00:00","error":null,"lastVerifiedAt":"2026-11-09T07:04:26.209+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13706,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-980593e6977a6d1b4fb1eed5a1ffe88a468736f89f0a06f710924ad59132c023","complete":true,"records":9914,"lastAttemptAt":"2026-11-09T08:02:26.1458433+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-09T08:02:26.1458433+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-fde804134ecdda0ddd5ff5c26ee1fff5a6fa659311f7ef2e51c6ad54964db0e2","complete":true,"records":1971,"lastAttemptAt":"2026-11-09T08:02:25.8338551+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-09T08:02:25.8338551+00:00","snapshotPublishedAt":"2026-11-06T18:17:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-f6d341f4320a5a0c059c28102ee651c3dd06abc87b84d2bafa4e2a823ec07d35","complete":true,"records":3056,"lastAttemptAt":"2026-11-09T08:02:26.1741996+00:00","lastSuccessAt":"2026-11-09T05:02:23.1539412+00:00","error":null,"lastVerifiedAt":"2026-11-09T08:02:26.1741996+00:00","snapshotPublishedAt":"2026-11-09T04:47:48+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-32fcf2a839d0d91a36b31c98096d6b8a1a8cc523d64745f8a939e306130e49f2","complete":true,"records":231296,"lastAttemptAt":"2026-11-09T08:02:25.9613255+00:00","lastSuccessAt":"2026-11-09T07:04:23.2641171+00:00","error":null,"lastVerifiedAt":"2026-11-09T08:02:25.9613255+00:00","snapshotPublishedAt":"2026-11-09T06:48:11+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}