{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2"
            },
            {
              "fixed": "f895191dc32c53eaf443b6443fe40945b2f92287"
            },
            {
              "fixed": "cd5beda7e0e32865e214f28034bb92c1cecff885"
            },
            {
              "fixed": "eaedc0bc18be46fe7f58170e967959a932c4f824"
            },
            {
              "fixed": "07a9b32eaae792ff7d0fcac14d8920c937c0a9c3"
            },
            {
              "fixed": "8b300f726640c48c3edfe9c453334dd801f4b74e"
            },
            {
              "fixed": "5e13d0a37666955b6cfddc0f73cb40ed645b8a05"
            },
            {
              "fixed": "f6c412dcfd76b0516d51aa847d8f4c7b70381b09"
            },
            {
              "fixed": "735ee8582da3d239eb0c7a53adca61b79fb228b3"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.12"
            },
            {
              "fixed": "5.10.252"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "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-2026-43190.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_tcpmss: check remaining length before reading optlen\n\nQuoting reporter:\n  In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads\n op[i+1] directly without validating the remaining option length.\n\n  If the last byte of the option field is not EOL/NOP (0/1), the code attempts\n  to index op[i+1]. In the case where i + 1 == optlen, this causes an\n  out-of-bounds read, accessing memory past the optlen boundary\n  (either reading beyond the stack buffer _opt or the\n  following payload).",
  "id": "CVE-2026-43190",
  "modified": "2026-07-08T05:37:13.836939142Z",
  "published": "2026-05-06T11:27:59.798Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/07a9b32eaae792ff7d0fcac14d8920c937c0a9c3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5e13d0a37666955b6cfddc0f73cb40ed645b8a05"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/735ee8582da3d239eb0c7a53adca61b79fb228b3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8b300f726640c48c3edfe9c453334dd801f4b74e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cd5beda7e0e32865e214f28034bb92c1cecff885"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/eaedc0bc18be46fe7f58170e967959a932c4f824"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f6c412dcfd76b0516d51aa847d8f4c7b70381b09"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f895191dc32c53eaf443b6443fe40945b2f92287"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43190.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43190"
    },
    {
      "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:L/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "netfilter: xt_tcpmss: check remaining length before reading optlen"
}