high7.5
CVE-2026-49866
libp2p: CPU DoS via oversized IHAVE and IWANT control message arrays
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @libp2p/gossipsub | < 16.0.0 | 16.0.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-cwc9-cp4j-mcvv
- https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cwc9-cp4j-mcvv
- https://nvd.nist.gov/vuln/detail/CVE-2026-49866
- 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