CVE-2026-34219
libp2p-gossipsub: Gossipsub PRUNE Backoff Heartbeat Instant Overflow
No known exploitation. EPSS puts it in the 42nd percentile. Fixed in 0.49.4.
What to do
Find your product and version, then upgrade to the build on the right.
- Libp2p Rust-libp2pAffected: < 0.49.4Upgrade to: not statedStated by: CVE record
- Protocol Libp2p-gossipsubAffected: < 0.49.4Upgrade to: 0.49.4Stated by: NVD
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
libp2p-rust is the official rust language Implementation of the libp2p networking stack. Prior to version 0.49.4, the Rust libp2p Gossipsub implementation contains a remotely reachable panic in backoff expiry handling. After a peer sends a crafted PRUNE control message with an attacker-controlled, near-maximum backoff value, the value is accepted and stored as an Instant near the representable upper bound. On a later heartbeat, the implementation performs unchecked Instant + Duration arithmetic (backoff_time + slack), which can overflow and panic with: overflow when adding duration to instant. This issue is reachable from any Gossipsub peer over normal TCP + Noise + mplex/yamux connectivity and requires no further authentication beyond becoming a protocol peer. This issue has been patched in version 0.49.4.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.5% chance of exploitation activity in the next 30 days, which ranks it in the 42nd percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
7 events over 115 days, from the signal feeds we watch.
- Patch availablerecord updated
- Patch availablerecord updated
- Publishedweakness classified, att&ck mapped
Affected products
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Scored 5.9 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality NoneNo confidentiality impact
- Integrity NoneNo integrity impact
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
Sources
References in the record
Watch the software you run.
My Stack ranks new CVEs for your products by real-world exploitation, so the next serious one reaches you without reading every advisory.
We'll flag the next CVE, public exploit or patch for Rust-libp2p, not every advisory.
A free account adds
- The full version matrix and every affected product
- Exploit links, proofs of concept and Metasploit modules
- Email alerts for the products you watch
- The same data over REST API, MCP and CLI