{
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          "product": "js-libp2p",
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              "version": "\u003c 16.0.0"
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          "lang": "en",
          "value": "libp2p is a JavaScript Implementation of libp2p networking stack. Prior to 16.0.0, @libp2p/gossipsub defaultDecodeRpcLimits set maxIhaveMessageIDs and maxIwantMessageIDs to Infinity, allowing oversized IHAVE and IWANT control message arrays in message/decodeRpc.ts and gossipsub.ts to synchronously iterate roughly 180,000 message IDs per 4 MB frame and block the Node.js event loop. This issue is fixed in version 16.0.0."
        }
      ],
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          "cvssV3_1": {
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            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/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": "2026-07-08T20:47:09.051Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cwc9-cp4j-mcvv",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cwc9-cp4j-mcvv"
        },
        {
          "name": "https://github.com/libp2p/js-libp2p/pull/3520",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libp2p/js-libp2p/pull/3520"
        },
        {
          "name": "https://github.com/libp2p/js-libp2p/commit/773dd80ded24dbd6b19e675c89fd2f3b45f2d899",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libp2p/js-libp2p/commit/773dd80ded24dbd6b19e675c89fd2f3b45f2d899"
        },
        {
          "name": "https://github.com/libp2p/js-libp2p/releases/tag/gossipsub-v16.0.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libp2p/js-libp2p/releases/tag/gossipsub-v16.0.0"
        }
      ],
      "source": {
        "advisory": "GHSA-cwc9-cp4j-mcvv",
        "discovery": "UNKNOWN"
      },
      "title": "libp2p: CPU DoS via oversized IHAVE and IWANT control message arrays"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-49866",
    "datePublished": "2026-07-08T20:47:09.051Z",
    "dateReserved": "2026-06-01T22:03:19.641Z",
    "dateUpdated": "2026-07-08T20:47:09.051Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-49866\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-07-08T21:16:49.137\",\"lastModified\":\"2026-07-08T21:16:49.137\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"libp2p is a JavaScript Implementation of libp2p networking stack. Prior to 16.0.0, @libp2p/gossipsub defaultDecodeRpcLimits set maxIhaveMessageIDs and maxIwantMessageIDs to Infinity, allowing oversized IHAVE and IWANT control message arrays in message/decodeRpc.ts and gossipsub.ts to synchronously iterate roughly 180,000 message IDs per 4 MB frame and block the Node.js event loop. This issue is fixed in version 16.0.0.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"libp2p\",\"product\":\"js-libp2p\",\"versions\":[{\"version\":\"\u003c 16.0.0\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-770\"}]}],\"references\":[{\"url\":\"https://github.com/libp2p/js-libp2p/commit/773dd80ded24dbd6b19e675c89fd2f3b45f2d899\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/libp2p/js-libp2p/pull/3520\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/libp2p/js-libp2p/releases/tag/gossipsub-v16.0.0\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cwc9-cp4j-mcvv\",\"source\":\"security-advisories@github.com\"}]}}"
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}