{"id":"CVE-2026-49866","state":"PUBLISHED","title":"libp2p: CPU DoS via oversized IHAVE and IWANT control message arrays","description":"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.","publishedAt":"2026-07-08T20:47:09.051Z","updatedAt":"2026-07-09T14:40:44.919Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["libp2p js-libp2p"],"affected":[{"vendor":"libp2p","product":"js-libp2p","versions":[{"version":"< 16.0.0","status":"affected"}]}],"references":["https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cwc9-cp4j-mcvv","https://github.com/libp2p/js-libp2p/pull/3520","https://github.com/libp2p/js-libp2p/commit/773dd80ded24dbd6b19e675c89fd2f3b45f2d899","https://github.com/libp2p/js-libp2p/releases/tag/gossipsub-v16.0.0"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/49xxx/CVE-2026-49866.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-49866","state":"PUBLISHED","datePublished":"2026-07-08T20:47:09.051Z","dateUpdated":"2026-07-09T14:40:44.919Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-01T22:03:19.641Z"},"containers":{"cna":{"title":"libp2p: CPU DoS via oversized IHAVE and IWANT control message arrays","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":[{"vendor":"libp2p","product":"js-libp2p","versions":[{"version":"< 16.0.0","status":"affected"}]}],"references":[{"url":"https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cwc9-cp4j-mcvv","name":"https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cwc9-cp4j-mcvv","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/libp2p/js-libp2p/pull/3520","name":"https://github.com/libp2p/js-libp2p/pull/3520","tags":["x_refsource_MISC"]},{"url":"https://github.com/libp2p/js-libp2p/commit/773dd80ded24dbd6b19e675c89fd2f3b45f2d899","name":"https://github.com/libp2p/js-libp2p/commit/773dd80ded24dbd6b19e675c89fd2f3b45f2d899","tags":["x_refsource_MISC"]},{"url":"https://github.com/libp2p/js-libp2p/releases/tag/gossipsub-v16.0.0","name":"https://github.com/libp2p/js-libp2p/releases/tag/gossipsub-v16.0.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","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","lang":"en","description":"CWE-770: Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-08T20:47:09.051Z"},"source":{"advisory":"GHSA-cwc9-cp4j-mcvv","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-09T14:37:59.412018Z","id":"CVE-2026-49866","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-09T14:40:44.919Z"}}]}}}