{"id":"CVE-2026-86040","title":"libp2p is a JavaScript implementation of the libp2p networking stack","summary":"libp2p is a JavaScript implementation of the libp2p networking stack. Prior to 11.0.26, @libp2p/floodsub accepts unauthenticated RPC frames on /floodsub/1.0.0 through PeerStreams.attachInboundStream in packages/floodsub/src/peer-streams.…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-400","CWE-401","CWE-770"],"vendor":"libp2p","product":"js-libp2p","affected":["js-libp2p < 11.0.26","floodsub < 11.0.26"],"published":"2026-09-17","updated":"2026-09-17","sourceUpdated":"2026-09-17T20:18:49.740","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-86040","references":[{"url":"https://github.com/libp2p/js-libp2p/commit/fb9e8a76e9ac75924928fae4ce11d00f68320a83","label":"security-advisories@github.com"},{"url":"https://github.com/libp2p/js-libp2p/pull/3568","label":"security-advisories@github.com"},{"url":"https://github.com/libp2p/js-libp2p/releases/tag/floodsub-v11.0.26","label":"security-advisories@github.com"},{"url":"https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cvfg-hcf3-ggwv","label":"security-advisories@github.com"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-17T17:06:11.592901Z"},"ingestedAt":"2026-09-17T16:21:47.715Z","epss":0.00373,"epssPercentile":0.31039,"slug":"CVE-2026-86040","body":"## Overview\n\nlibp2p is a JavaScript implementation of the libp2p networking stack. Prior to 11.0.26, @libp2p/floodsub accepts unauthenticated RPC frames on /floodsub/1.0.0 through PeerStreams.attachInboundStream in packages/floodsub/src/peer-streams.ts without protobuf element limits, then processRpc and processRpcSubOpt in packages/floodsub/src/floodsub.ts synchronously process the subscriptions array without a per-frame cap. A single bounded-size frame can decode into millions of empty subscription entries that block the event loop, while hundreds of thousands of unique-topic SUBSCRIBE entries allocate PeerSet objects in this.topics that are not removed after peer removal or stop. Empty entries cause CPU exhaustion but do not grow this.topics; persistent memory growth requires unique topics. The subscription path bypasses message signature validation and the message-only processing queue, allowing a remote peer to cause sustained CPU denial of service, memory exhaustion, out-of-memory termination, and node unavailability. The issue is fixed in version 11.0.26.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}