CVE-2026-49866CWE-770

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

High · published July 8, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
49.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00630 · 49.5th percentile
Weakness
CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-07-08T20:47Z
EPSS history
Timeline
  • 08 JUL 20:47Z
    libp2p: CPU DoS via oversized IHAVE and IWANT control message arrays
    cvelistv5