CVE-2026-47184 (GCVE-0-2026-47184)

Vulnerability from cvelistv5 – Published: 2026-07-17 18:25 – Updated: 2026-07-17 18:25
VLAI
Title
Zeroconf: Unbounded DNS record cache allows LAN-local memory exhaustion via multicast flood
Summary
Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.7, DNSCache._async_add inserted every response record into cache, _expirations, _expire_heap, and service_cache without a cap, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to multicast valid mDNS responses with unique names and cause memory exhaustion, slower cache lookups, slower async_expire passes, and broken discovery, registration, and ServiceBrowser callbacks. This issue is fixed in version 0.149.7.
Severity
6.5 (Medium)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
Impacted products
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "python-zeroconf",
          "vendor": "python-zeroconf",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.149.7"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.7, DNSCache._async_add inserted every response record into cache, _expirations, _expire_heap, and service_cache without a cap, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to multicast valid mDNS responses with unique names and cause memory exhaustion, slower cache lookups, slower async_expire passes, and broken discovery, registration, and ServiceBrowser callbacks. This issue is fixed in version 0.149.7."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "ADJACENT_NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-17T18:25:07.387Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-rfg2-pjw2-56x2",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-rfg2-pjw2-56x2"
        },
        {
          "name": "https://github.com/python-zeroconf/python-zeroconf/issues/1715",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/python-zeroconf/python-zeroconf/issues/1715"
        },
        {
          "name": "https://github.com/python-zeroconf/python-zeroconf/pull/1718",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/python-zeroconf/python-zeroconf/pull/1718"
        },
        {
          "name": "https://github.com/python-zeroconf/python-zeroconf/commit/0ad3f37b5b852b8f614d322283d148efb2cef6e4",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/python-zeroconf/python-zeroconf/commit/0ad3f37b5b852b8f614d322283d148efb2cef6e4"
        },
        {
          "name": "https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.7",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.7"
        }
      ],
      "source": {
        "advisory": "GHSA-rfg2-pjw2-56x2",
        "discovery": "UNKNOWN"
      },
      "title": "Zeroconf: Unbounded DNS record cache allows LAN-local memory exhaustion via multicast flood"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-47184",
    "datePublished": "2026-07-17T18:25:07.387Z",
    "dateReserved": "2026-05-18T22:07:37.434Z",
    "dateUpdated": "2026-07-17T18:25:07.387Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-47184",
      "date": "2026-06-14",
      "epss": "0.00023",
      "percentile": "0.06699"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-47184\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-07-17T19:17:15.440\",\"lastModified\":\"2026-07-17T19:17:15.440\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.7, DNSCache._async_add inserted every response record into cache, _expirations, _expire_heap, and service_cache without a cap, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to multicast valid mDNS responses with unique names and cause memory exhaustion, slower cache lookups, slower async_expire passes, and broken discovery, registration, and ServiceBrowser callbacks. This issue is fixed in version 0.149.7.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"python-zeroconf\",\"product\":\"python-zeroconf\",\"versions\":[{\"version\":\"\u003c 0.149.7\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":6.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"ADJACENT_NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-770\"}]}],\"references\":[{\"url\":\"https://github.com/python-zeroconf/python-zeroconf/commit/0ad3f37b5b852b8f614d322283d148efb2cef6e4\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/python-zeroconf/python-zeroconf/issues/1715\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/python-zeroconf/python-zeroconf/pull/1718\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.7\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-rfg2-pjw2-56x2\",\"source\":\"security-advisories@github.com\"}]}}"
  }
}



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