{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "25.12.5"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "f0a60eee2fe051741c643ea6118718aae1ef17fb"
            }
          ],
          "repo": "https://github.com/openwrt/openwrt",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-9558-77jp-g3fw"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-191"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55490.json"
  },
  "details": "OpenWrt is a Linux operating system targeting embedded devices. Before v25.12.5, an integer underflow in handle_send_a() of the Emergency Access Daemon allows any unauthenticated attacker on the local network to crash the daemon by sending a single crafted UDP packet. The message length underflows before a bounds check and is then passed to memcpy as a very large size. This issue is fixed v25.12.5.",
  "id": "CVE-2026-55490",
  "modified": "2026-07-10T03:54:30.146440314Z",
  "published": "2026-07-07T21:08:26.638Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/openwrt/openwrt/releases/tag/v25.12.5"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55490.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/openwrt/openwrt/security/advisories/GHSA-9558-77jp-g3fw"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55490"
    },
    {
      "type": "FIX",
      "url": "https://github.com/openwrt/openwrt/commit/63c0767f3d02f7b10b0f0b5293366bd059a08ca5"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "OpenWrt: EAD Integer Underflow → Pre-Auth Denial of Service"
}