What’s Vulnerable › Vulnerabilities
CVE-2026-34219: libp2p-gossipsub: Gossipsub PRUNE Backoff Heartbeat Instant Overflow
- Severity: medium (CVSS 5.9 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.6% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2026-03-31 · updated 2026-07-24
- Weakness: CWE-190
Description
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.
Affected products
- Protocol Libp2P-Gossipsub: before 0.49.4 — fixed in 0.49.4
How to fix
Upgrade to a fixed version: Protocol Libp2P-Gossipsub 0.49.4. Check the vendor advisory for mitigations.
References
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