CVE-2026-34219
libp2p-gossipsub: Remote crash via unchecked Instant overflow in heartbeat backoff expiry handling
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rust | libp2p-gossipsub | < 0.49.4 | 0.49.4 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Protocol | Libp2p-Gossipsub | before 0.49.4 |