{"id":"CVE-2026-86040","state":"PUBLISHED","title":"libp2p: Unbounded RPC decode + synchronous subscription processing in @libp2p/floodsub allows unauthenticated DoS","description":"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.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.","publishedAt":"2026-09-17T15:20:40.724Z","updatedAt":"2026-09-17T19:19:11.341Z","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","@libp2p floodsub"],"affected":[{"vendor":"libp2p","product":"js-libp2p","versions":[{"version":"< 11.0.26","status":"affected"}]},{"vendor":"@libp2p","product":"floodsub","versions":[{"version":"< 11.0.26","status":"affected"}]}],"references":["https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cvfg-hcf3-ggwv","https://github.com/libp2p/js-libp2p/pull/3568","https://github.com/libp2p/js-libp2p/commit/fb9e8a76e9ac75924928fae4ce11d00f68320a83","https://github.com/libp2p/js-libp2p/releases/tag/floodsub-v11.0.26"],"weaknesses":["CWE-400","CWE-401","CWE-770"],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/86xxx/CVE-2026-86040.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-86040","state":"PUBLISHED","datePublished":"2026-09-17T15:20:40.724Z","dateUpdated":"2026-09-17T19:19:11.341Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-04T19:29:21.058Z"},"containers":{"cna":{"title":"libp2p: Unbounded RPC decode + synchronous subscription processing in @libp2p/floodsub allows unauthenticated DoS","descriptions":[{"lang":"en","value":"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.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."}],"affected":[{"vendor":"libp2p","product":"js-libp2p","versions":[{"version":"< 11.0.26","status":"affected"}]},{"vendor":"@libp2p","product":"floodsub","versions":[{"version":"< 11.0.26","status":"affected"}]}],"references":[{"url":"https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cvfg-hcf3-ggwv","name":"https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cvfg-hcf3-ggwv","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/libp2p/js-libp2p/pull/3568","name":"https://github.com/libp2p/js-libp2p/pull/3568","tags":["x_refsource_MISC"]},{"url":"https://github.com/libp2p/js-libp2p/commit/fb9e8a76e9ac75924928fae4ce11d00f68320a83","name":"https://github.com/libp2p/js-libp2p/commit/fb9e8a76e9ac75924928fae4ce11d00f68320a83","tags":["x_refsource_MISC"]},{"url":"https://github.com/libp2p/js-libp2p/releases/tag/floodsub-v11.0.26","name":"https://github.com/libp2p/js-libp2p/releases/tag/floodsub-v11.0.26","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-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-401","lang":"en","description":"CWE-401: Missing Release of Memory after Effective Lifetime","type":"CWE"}]},{"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":"2026-09-17T15:20:40.724Z"},"source":{"advisory":"GHSA-cvfg-hcf3-ggwv","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-17T17:06:11.592901Z","id":"CVE-2026-86040","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":"2026-09-17T19:19:11.341Z"}}]}}}