CVE-2026-46679: libp2p js-libp2p memory exhaustion in @libp2p/gossipsub

CVE-2026-46679 · Severity: high · CVSS 7.5 · Published 2026-06-10

The GossipSub component of libp2p, used for peer-to-peer message routing in decentralized networks, contains a memory exhaustion vulnerability. An attacker can send specially crafted subscription messages containing thousands of unique topics to cause a Node.js process to consume excessive memory and crash within seconds. This affects any application using the vulnerable library on a public network without authentication requirements.

Technologies: Libp2p Gossipsub, @libp2p/gossipsub (npm). Vendors: Libp2p, npm.

Quick answers

Is CVE-2026-46679 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-46679 being exploited in the wild.
How severe is CVE-2026-46679?
High severity, with a CVSS score of 7.5, published 10 June 2026.
Which products and versions are affected?
Libp2p Gossipsub <= 15.0.22, <=15.0.22; @libp2p/gossipsub (npm) <= 15.0.22, SEMVER:introduced=0,fixed=15.0.23.
Is there a fix for CVE-2026-46679?
Yes. @libp2p/gossipsub (npm): upgrade to 15.0.23 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-46679 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-46679?
Check whether you run Libp2p Gossipsub or @libp2p/gossipsub (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • @libp2p/gossipsub (npm): upgrade to 15.0.23 or later
    npm install @libp2p/gossipsub@15.0.23

Technical details

The vulnerability arises from three compounding issues in @libp2p/gossipsub: (1) no decode-level cap on subscription entries per RPC (defaultDecodeRpcLimits.maxSubscriptions = Infinity), allowing a single 4MB frame to carry ~349K unique SUBSCRIBE entries; (2) unbounded growth of the this.topics map with no per-peer subscription limit, creating new Map/Set entries for every unique topic string; (3) a memory leak in removePeer() that retains empty Sets after peer disconnection, making memory non-reclaimable for the process lifetime. An unauthenticated attacker can open a gossipsub stream and repeatedly send RPCs with sequential unique topic subscriptions, achieving ~22x memory amplification (4MB attacker payload → ~89MB heap consumption) per frame. A Node.js process with default 1.5GB heap limit crashes after ~17 frames (~68MB total bandwidth). Patch version 15.0.23 and later address these defects.

Affected products

  • libp2p @libp2p/gossipsub <=15.0.22

Identifiers

  • CVE-2026-46679
  • GHSA-4f8r-922h-2vgv

Timeline

  • 2026-05-21: disclosed
  • 2026-05-21: patched: patch version 15.0.23

References

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