{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "11.0.26"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "fb9e8a76e9ac75924928fae4ce11d00f68320a83"
            },
            {
              "fixed": "59ccecc405e49b81ade4218b84a16c036b340b61"
            }
          ],
          "repo": "https://github.com/libp2p/js-libp2p",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-cvfg-hcf3-ggwv"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-400",
      "CWE-401",
      "CWE-770"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86040.json"
  },
  "details": "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.",
  "id": "CVE-2026-86040",
  "modified": "2026-09-19T03:30:51.956315303Z",
  "published": "2026-09-17T15:20:40.724Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/libp2p/js-libp2p/releases/tag/floodsub-v11.0.26"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86040.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cvfg-hcf3-ggwv"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-86040"
    },
    {
      "type": "FIX",
      "url": "https://github.com/libp2p/js-libp2p/commit/fb9e8a76e9ac75924928fae4ce11d00f68320a83"
    },
    {
      "type": "FIX",
      "url": "https://github.com/libp2p/js-libp2p/pull/3568"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "libp2p: Unbounded RPC decode + synchronous subscription processing in @libp2p/floodsub allows unauthenticated DoS"
}