{"id":"CVE-2026-99042","revision":"f500282cb2aa4208ae9bc5620b583b59","records":[{"revision":"f500282cb2aa4208ae9bc5620b583b59","observedAt":"2026-10-24T16:17:04.479+00:00","statement":{"source":"cve-program","id":"CVE-2026-99042","aliases":[],"title":"io_uring/net: populate CONNECT filter fields for 24-byte sockaddr_in6","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/net: populate CONNECT filter fields for 24-byte sockaddr_in6\n\nio_connect_bpf_populate() fills connect.port and connect.v6_addr for\nAF_INET6 only when addr_len >= sizeof(struct sockaddr_in6), i.e. 28\nbytes.\n\nThe IPv6 connect paths accept SIN6_LEN_RFC2133 (24 bytes), which\nalready holds sin6_port and sin6_addr. io_connect() passes addr_len to\nthe socket layer unchanged.\n\nAt addr_len 24 the filter sees family AF_INET6 with port and address\nzero, while the kernel connects to the real destination. A filter that\ndenies an IPv6 port or address is bypassed. Denying connect.port == P\nrejects [::1]:P with -EACCES at addr_len 28 but connects at addr_len 24.\n\nUse SIN6_LEN_RFC2133 as the threshold. sin6_scope_id stays zero when\nabsent.\n\nThe threshold mismatch was found by an AI coding assistant (Claude Code)\ncomparing this hook against the net/ipv6 length checks on my\ninstructions; it also drafted the reproducer and this patch. I verified\nthe bypass and the fix in a VM on 7.3-rc6 and that 7.2 has the same\ncode.","state":0,"publishedAt":"2026-10-23T12:22:01.804+00:00","modifiedAt":"2026-10-24T14:10:09.161+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                        \"io_uring/net.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"899bea8248cee35d54760a5e7d61a76af8e64411\",\n                            \"lessThan\": \"596a955d2d01b7e29d9fed60ebcf7c4ba518b8e5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"899bea8248cee35d54760a5e7d61a76af8e64411\",\n                            \"lessThan\": \"aa5d5f8e502318e783545ba5d04bb40130b83e20\",\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                        \"io_uring/net.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"7.2\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"7.2\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.11\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","score":8.4,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/596a955d2d01b7e29d9fed60ebcf7c4ba518b8e5","https://git.kernel.org/stable/c/aa5d5f8e502318e783545ba5d04bb40130b83e20"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99042","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-99042","identifiers":["CVE-2026-99042"]},"retained":false,"historicalAffected":[]}],"coverage":[]}