{"cve":"CVE-2026-49866","nvd":{"published":"2026-07-08T21:16:49.137","modified":"2026-10-25T17:10:00.197","status":"Deferred","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-770"],"references":["https://github.com/libp2p/js-libp2p/commit/773dd80ded24dbd6b19e675c89fd2f3b45f2d899","https://github.com/libp2p/js-libp2p/pull/3520","https://github.com/libp2p/js-libp2p/releases/tag/gossipsub-v16.0.0","https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cwc9-cp4j-mcvv"],"products":[],"source":"nvd","synced_at":"2026-10-25T17:50:06.907763985+00:00"},"epss":{"cve":"CVE-2026-49866","score":0.0063,"percentile":0.49881,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-cwc9-cp4j-mcvv","url":"https://osv.dev/vulnerability/GHSA-cwc9-cp4j-mcvv","summary":"libp2p: CPU DoS via oversized IHAVE and IWANT control message arrays","modified":"2026-07-10T16:15:10.853144805Z","packages":[{"ecosystem":"npm","name":"@libp2p/gossipsub","purl":"pkg:npm/%40libp2p/gossipsub","ranges":["<16.0.0"],"fixed":["16.0.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}