{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.2.11-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  io_uring/net: populate CONNECT filter fields for 24-byte sockaddr_in6  io_connect_bpf_populate() fills connect.port and connect.v6_addr for AF_INET6 only when addr_len \u003e= sizeof(struct sockaddr_in6), i.e. 28 bytes.  The IPv6 connect paths accept SIN6_LEN_RFC2133 (24 bytes), which already holds sin6_port and sin6_addr. io_connect() passes addr_len to the socket layer unchanged.  At addr_len 24 the filter sees family AF_INET6 with port and address zero, while the kernel connects to the real destination. A filter that denies an IPv6 port or address is bypassed. Denying connect.port == P rejects [::1]:P with -EACCES at addr_len 28 but connects at addr_len 24.  Use SIN6_LEN_RFC2133 as the threshold. sin6_scope_id stays zero when absent.  The threshold mismatch was found by an AI coding assistant (Claude Code) comparing this hook against the net/ipv6 length checks on my instructions; it also drafted the reproducer and this patch. I verified the bypass and the fix in a VM on 7.3-rc6 and that 7.2 has the same code.",
  "id": "DEBIAN-CVE-2026-99042",
  "modified": "2026-10-25T09:47:38.379000353Z",
  "published": "2026-10-23T13:17:27.610Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-99042"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-99042"
  ]
}