{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "9ee11f0fff205b4b3df9750bff5e94f97c71b6a0"
            },
            {
              "fixed": "f4d9d4b8fd839719d564651671e24c62c545c23b"
            },
            {
              "fixed": "fb3c662fafebc5b9d74417ed1de8759f6bb72143"
            },
            {
              "fixed": "632d233cf2e64a46865ae2c064ae3c9df7c8864f"
            },
            {
              "fixed": "0591d6509c2ff13f09ea2998434aba0c0472e978"
            },
            {
              "fixed": "e90346a2f1e8917d5760a44a1f61c44e3b36d96b"
            },
            {
              "fixed": "ea3632aefc04205436868541638e26f4a74d5637"
            },
            {
              "fixed": "6db8b56eed62baacaf37486e83378a72635c04cc"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.15.0"
            },
            {
              "fixed": "5.15.202"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.165"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.128"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.75"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.16"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43186.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()\n\nOn the receive path, __ioam6_fill_trace_data() uses trace-\u003enodelen\nto decide how much data to write for each node. It trusts this field\nas-is from the incoming packet, with no consistency check against\ntrace-\u003etype (the 24-bit field that tells which data items are\npresent). A crafted packet can set nodelen=0 while setting type bits\n0-21, causing the function to write ~100 bytes past the allocated\nregion (into skb_shared_info), which corrupts adjacent heap memory\nand leads to a kernel panic.\n\nAdd a shared helper ioam6_trace_compute_nodelen() in ioam6.c to\nderive the expected nodelen from the type field, and use it:\n\n  - in ioam6_iptunnel.c (send path, existing validation) to replace\n    the open-coded computation;\n  - in exthdrs.c (receive path, ipv6_hop_ioam) to drop packets whose\n    nodelen is inconsistent with the type field, before any data is\n    written.\n\nPer RFC 9197, bits 12-21 are each short (4-octet) fields, so they\nare included in IOAM6_MASK_SHORT_FIELDS (changed from 0xff100000 to\n0xff1ffc00).",
  "id": "CVE-2026-43186",
  "modified": "2026-07-08T05:39:18.709877824Z",
  "published": "2026-05-06T11:27:57.053Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0591d6509c2ff13f09ea2998434aba0c0472e978"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/632d233cf2e64a46865ae2c064ae3c9df7c8864f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6db8b56eed62baacaf37486e83378a72635c04cc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e90346a2f1e8917d5760a44a1f61c44e3b36d96b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ea3632aefc04205436868541638e26f4a74d5637"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f4d9d4b8fd839719d564651671e24c62c545c23b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fb3c662fafebc5b9d74417ed1de8759f6bb72143"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43186.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43186"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()"
}