CVE-2026-55606

{
  "id": "CVE-2026-55606",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-23T14:17:53.850",
  "lastModified": "2026-10-29T18:17:33.527",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. In versions 25.12 and prior, odhcpd's DHCPv6 self-loop detection at dhcpv6.c:720 uses a network-byte-order DUID length value directly as the memcmp() size parameter. On little-endian hosts, this causes memcmp() to read far beyond the stack buffer — a single unauthenticated DHCPv6 packet triggers a 2560-byte overread from a 128-byte buffer. At time of publication, there are no publicly available patches."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "openwrt",
          "product": "odhcpd",
          "versions": [
            {
              "version": "<= 25.12",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 2.5
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-29T17:43:15.504706Z",
          "id": "CVE-2026-55606",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-126"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/openwrt/odhcpd/commit/6907f28f9ddeef9f69f5ee10bbc9ba8adc0ef57f",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/openwrt/odhcpd/commit/ed38cffa927d5fd450d20bfd3f7fb8d8e8fff301",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/openwrt/odhcpd/pull/401",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-x8x4-7gvf-gp45",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-x8x4-7gvf-gp45",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}