Skip to content
OpenAdvisories
High · 7.5 CVE-2026-49866 EUVD-2026-42409GHSA-cwc9-cp4j-mcvv

libp2p: CPU DoS via oversized IHAVE and IWANT control message arrays

Published Jul 8, 2026 · Updated Jul 9, 2026 · Assigned by GitHub_M

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 products

VendorProductAffectedFixed
libp2p js-libp2p < 16.0.0 —

Affected packages

EcosystemPackageAffectedFixedRecord
npm @libp2p/gossipsub < 16.0.0 16.0.0 GHSA-cwc9-cp4j-mcvv

References