{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "130c0f47fdf9c533deb1136cad5136f6cb7020f0"
            },
            {
              "fixed": "abcba6f080c63e403037ecdffde43170d242376a"
            },
            {
              "fixed": "24e79508b237dd2a69bc6fb6ac5cf7f126178307"
            },
            {
              "fixed": "cbaad2922bd5d4d303055ae9afecc8999e6b40c9"
            },
            {
              "fixed": "e47a1958e12abc3a17b5231a4f21c8f1bf662e08"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.36"
            },
            {
              "fixed": "6.12.112"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.55"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98493.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ipconfig: bound DHCP option construction\n\nic_dhcp_init_options() appends the hostname (option 12), vendor-class\n(option 60) and client-ID (option 61) options into the fixed 312-byte\nbootp_pkt.exten[] buffer.  Only the client-ID branch checked the\nremaining space; the hostname and vendor-class writes were unbounded.\n\nA 64-byte hostname together with the maximum 252-byte dhcpclass=\nidentifier needs 18 + (2 + 64) + (2 + 252) = 338 of the 312 available\nbytes even before the terminating END marker, so the vendor-class memcpy\nruns past the end of exten[].  With CONFIG_FORTIFY_SOURCE this is\nreported as a field-spanning write and, when the kernel is booted with\npanic_on_warn=1, aborts boot with a panic.\n\nRoute the optional options through a common helper that makes sure the\noption, its 2-byte header and the END marker all fit and drops an option\nthat would not.  Configurations with short options keep sending exactly\nthe same bytes as before.",
  "id": "CVE-2026-98493",
  "modified": "2026-10-20T02:30:45.726305195Z",
  "published": "2026-10-18T15:16:22.301Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/24e79508b237dd2a69bc6fb6ac5cf7f126178307"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/abcba6f080c63e403037ecdffde43170d242376a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cbaad2922bd5d4d303055ae9afecc8999e6b40c9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e47a1958e12abc3a17b5231a4f21c8f1bf662e08"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98493.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98493"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "net: ipconfig: bound DHCP option construction"
}