{
 "id": "CVE-2026-99042",
 "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.",
 "published": "2026-10-23",
 "last_modified": "2026-10-24",
 "vuln_status": "Received",
 "cna": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
 "cvss": {
  "version": "3.1",
  "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",
  "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
 },
 "cwe": [],
 "products": [
  {
   "vendor": "Anthropic",
   "product": "Claude Code",
   "versions_affected": null,
   "fixed_in": null,
   "product_id": "claude-code"
  }
 ],
 "category": "product",
 "surface": [],
 "kev": null,
 "fix": {
  "status": "unknown",
  "version": null,
  "url": null
 },
 "references": [
  {
   "url": "https://git.kernel.org/stable/c/596a955d2d01b7e29d9fed60ebcf7c4ba518b8e5",
   "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
   "tags": []
  },
  {
   "url": "https://git.kernel.org/stable/c/aa5d5f8e502318e783545ba5d04bb40130b83e20",
   "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
   "tags": []
  }
 ],
 "related_agents": [
  "anthropic-claude-code"
 ],
 "related_incidents": [],
 "match": {
  "tests": [
   "A:name"
  ],
  "terms": [
   "claude-code:Claude Code"
  ]
 },
 "status": "candidate",
 "note": null,
 "reviewer": null,
 "checked_on": null,
 "retrieved_on": "2026-10-26"
}