High severityNVD Advisory· Published Jul 8, 2026· Updated Jul 9, 2026
libp2p: CPU DoS via oversized IHAVE and IWANT control message arrays
CVE-2026-49866
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.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
@libp2p/gossipsubnpm | < 16.0.0 | 16.0.0 |
Affected products
2Patches
Vulnerability mechanics
References
6- github.com/advisories/GHSA-cwc9-cp4j-mcvvghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-49866ghsaADVISORY
- github.com/libp2p/js-libp2p/commit/773dd80ded24dbd6b19e675c89fd2f3b45f2d899ghsax_refsource_MISCWEB
- github.com/libp2p/js-libp2p/pull/3520ghsax_refsource_MISCWEB
- github.com/libp2p/js-libp2p/releases/tag/gossipsub-v16.0.0ghsax_refsource_MISCWEB
- github.com/libp2p/js-libp2p/security/advisories/GHSA-cwc9-cp4j-mcvvghsax_refsource_CONFIRMWEB
News mentions
0No linked articles in our index yet.