CVE-2026-34219: libp2p rust-libp2p denial of service in Gossipsub heartbeat

CVE-2026-34219 · Severity: medium · CVSS 5.9 · Published 2026-03-31

A vulnerability in the Rust implementation of the libp2p networking stack allows a remote attacker to crash a target node. By sending a specially crafted message, an attacker can trigger a system failure (panic) during the software's internal heartbeat process. This results in a denial-of-service, potentially disrupting decentralized applications or blockchain nodes that rely on this networking library.

Vendors: crates.io, Libp2p.

Quick answers

Is CVE-2026-34219 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-34219 being exploited in the wild.
How severe is CVE-2026-34219?
Medium severity, with a CVSS score of 5.9, published 31 March 2026.
Which products and versions are affected?
libp2p-gossipsub (crates.io) SEMVER:introduced=0,fixed=0.49.4; Libp2p Rust-Libp2p-Gossipsub < 0.49.4.
Is there a fix for CVE-2026-34219?
Yes. libp2p-gossipsub (crates.io): upgrade to 0.49.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-34219 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-34219?
Check whether you run libp2p-gossipsub (crates.io) or Libp2p Rust-Libp2p-Gossipsub 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 (crates.io): upgrade to 0.49.4 or later
    cargo update -p libp2p-gossipsub

Technical details

The vulnerability exists in the Gossipsub implementation of rust-libp2p due to unchecked arithmetic in the heartbeat expiry logic. An attacker can send a crafted PRUNE control message containing a near-maximum backoff value. While the initial storage of this value uses checked addition, a subsequent heartbeat process performs unchecked 'Instant + Duration' arithmetic (backoff_time + slack). This causes an integer overflow and a process panic. The issue is reachable by any unauthenticated peer over standard TCP + Noise connectivity and has been patched in version 0.49.4.

Affected products

  • libp2p rust-libp2p-gossipsub < 0.49.4

Identifiers

  • CVE-2026-34219
  • GHSA-xqmp-fxgv-xvq5

Timeline

  • 2026-03-27: advisory: GitHub Security Advisory published
  • 2026-03-31: disclosed: CVE published to NVD

References

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