{"api_version":"1","generated_at":"2026-07-22T17:02:32+00:00","cve":"CVE-2026-63828","urls":{"html":"https://cve.report/CVE-2026-63828","api":"https://cve.report/api/cve/CVE-2026-63828.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-63828","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-63828"},"summary":{"title":"apparmor: mediate the implicit connect of TCP fast open sendmsg","description":"In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: mediate the implicit connect of TCP fast open sendmsg\n\nsendmsg()/sendto() with MSG_FASTOPEN is a combination of connect(2) and\nwrite(2): it opens the connection in the SYN. apparmor_socket_sendmsg()\nonly checks AA_MAY_SEND, so a profile that grants send but denies connect\nlets a confined task open an outbound TCP/MPTCP connection that connect(2)\nwould have refused, bypassing connect mediation.\n\nMediate the implicit connect when MSG_FASTOPEN is set and a destination\nis supplied. Add it to apparmor_socket_sendmsg() (not the shared\naa_sock_msg_perm() helper, which recvmsg also uses) and call aa_sk_perm()\ndirectly, mirroring the selinux and tomoyo fixes. sk_is_tcp() does not\ncover MPTCP fast open, so the SOCK_STREAM/IPPROTO_MPTCP arm is explicit.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-19 12:16:56","updated_at":"2026-07-20 15:16:49"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"8.4","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","baseScore":8.4,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"8.4","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","data":{"baseScore":8.4,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/7f57428ce00891d26b0f087ef754a4d820ec83aa","name":"https://git.kernel.org/stable/c/7f57428ce00891d26b0f087ef754a4d820ec83aa","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/45ebb934ea50b436ce49b2f159f090dab0d7fa28","name":"https://git.kernel.org/stable/c/45ebb934ea50b436ce49b2f159f090dab0d7fa28","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/4d587cd8a72155089a627130bbd4716ec0856e21","name":"https://git.kernel.org/stable/c/4d587cd8a72155089a627130bbd4716ec0856e21","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/faea60deaa05c76f0772650f42eafde12bd39d93","name":"https://git.kernel.org/stable/c/faea60deaa05c76f0772650f42eafde12bd39d93","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/4a69b83045d3195d5b9a9b053ad840ddb2998b4e","name":"https://git.kernel.org/stable/c/4a69b83045d3195d5b9a9b053ad840ddb2998b4e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/07b71c342382b854ab8030b244aeab6a7228ad7d","name":"https://git.kernel.org/stable/c/07b71c342382b854ab8030b244aeab6a7228ad7d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63828","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63828","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cf60af03ca4e71134206809ea892e49b92a88896 7f57428ce00891d26b0f087ef754a4d820ec83aa git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cf60af03ca4e71134206809ea892e49b92a88896 faea60deaa05c76f0772650f42eafde12bd39d93 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cf60af03ca4e71134206809ea892e49b92a88896 07b71c342382b854ab8030b244aeab6a7228ad7d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cf60af03ca4e71134206809ea892e49b92a88896 4a69b83045d3195d5b9a9b053ad840ddb2998b4e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cf60af03ca4e71134206809ea892e49b92a88896 45ebb934ea50b436ce49b2f159f090dab0d7fa28 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cf60af03ca4e71134206809ea892e49b92a88896 4d587cd8a72155089a627130bbd4716ec0856e21 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3.6","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 3.6 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.177 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.144 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.95 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.38 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.3 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"63828","cve":"CVE-2026-63828","epss":"0.001690000","percentile":"0.066020000","score_date":"2026-07-20","updated_at":"2026-07-21 00:13:14"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["security/apparmor/lsm.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"7f57428ce00891d26b0f087ef754a4d820ec83aa","status":"affected","version":"cf60af03ca4e71134206809ea892e49b92a88896","versionType":"git"},{"lessThan":"faea60deaa05c76f0772650f42eafde12bd39d93","status":"affected","version":"cf60af03ca4e71134206809ea892e49b92a88896","versionType":"git"},{"lessThan":"07b71c342382b854ab8030b244aeab6a7228ad7d","status":"affected","version":"cf60af03ca4e71134206809ea892e49b92a88896","versionType":"git"},{"lessThan":"4a69b83045d3195d5b9a9b053ad840ddb2998b4e","status":"affected","version":"cf60af03ca4e71134206809ea892e49b92a88896","versionType":"git"},{"lessThan":"45ebb934ea50b436ce49b2f159f090dab0d7fa28","status":"affected","version":"cf60af03ca4e71134206809ea892e49b92a88896","versionType":"git"},{"lessThan":"4d587cd8a72155089a627130bbd4716ec0856e21","status":"affected","version":"cf60af03ca4e71134206809ea892e49b92a88896","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["security/apparmor/lsm.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"3.6"},{"lessThan":"3.6","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.177","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.144","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.95","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.38","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.3","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.177","versionStartIncluding":"3.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.144","versionStartIncluding":"3.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.95","versionStartIncluding":"3.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.38","versionStartIncluding":"3.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.3","versionStartIncluding":"3.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc1","versionStartIncluding":"3.6","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: mediate the implicit connect of TCP fast open sendmsg\n\nsendmsg()/sendto() with MSG_FASTOPEN is a combination of connect(2) and\nwrite(2): it opens the connection in the SYN. apparmor_socket_sendmsg()\nonly checks AA_MAY_SEND, so a profile that grants send but denies connect\nlets a confined task open an outbound TCP/MPTCP connection that connect(2)\nwould have refused, bypassing connect mediation.\n\nMediate the implicit connect when MSG_FASTOPEN is set and a destination\nis supplied. Add it to apparmor_socket_sendmsg() (not the shared\naa_sock_msg_perm() helper, which recvmsg also uses) and call aa_sk_perm()\ndirectly, mirroring the selinux and tomoyo fixes. sk_is_tcp() does not\ncover MPTCP fast open, so the SOCK_STREAM/IPPROTO_MPTCP arm is explicit."}],"metrics":[{"cvssV3_1":{"baseScore":8.4,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-20T13:40:31.639Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/7f57428ce00891d26b0f087ef754a4d820ec83aa"},{"url":"https://git.kernel.org/stable/c/faea60deaa05c76f0772650f42eafde12bd39d93"},{"url":"https://git.kernel.org/stable/c/07b71c342382b854ab8030b244aeab6a7228ad7d"},{"url":"https://git.kernel.org/stable/c/4a69b83045d3195d5b9a9b053ad840ddb2998b4e"},{"url":"https://git.kernel.org/stable/c/45ebb934ea50b436ce49b2f159f090dab0d7fa28"},{"url":"https://git.kernel.org/stable/c/4d587cd8a72155089a627130bbd4716ec0856e21"}],"title":"apparmor: mediate the implicit connect of TCP fast open sendmsg","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-63828","datePublished":"2026-07-19T12:02:22.644Z","dateReserved":"2026-07-19T07:54:57.014Z","dateUpdated":"2026-07-20T13:40:31.639Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-19 12:16:56","lastModifiedDate":"2026-07-20 15:16:49","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","baseScore":8.4,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE"},"exploitabilityScore":2,"impactScore":5.8}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"63828","Ordinal":"1","Title":"apparmor: mediate the implicit connect of TCP fast open sendmsg","CVE":"CVE-2026-63828","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"63828","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: mediate the implicit connect of TCP fast open sendmsg\n\nsendmsg()/sendto() with MSG_FASTOPEN is a combination of connect(2) and\nwrite(2): it opens the connection in the SYN. apparmor_socket_sendmsg()\nonly checks AA_MAY_SEND, so a profile that grants send but denies connect\nlets a confined task open an outbound TCP/MPTCP connection that connect(2)\nwould have refused, bypassing connect mediation.\n\nMediate the implicit connect when MSG_FASTOPEN is set and a destination\nis supplied. Add it to apparmor_socket_sendmsg() (not the shared\naa_sock_msg_perm() helper, which recvmsg also uses) and call aa_sk_perm()\ndirectly, mirroring the selinux and tomoyo fixes. sk_is_tcp() does not\ncover MPTCP fast open, so the SOCK_STREAM/IPPROTO_MPTCP arm is explicit.","Type":"Description","Title":"apparmor: mediate the implicit connect of TCP fast open sendmsg"}]}}}