Vulnerability · Published Mar 31, 2026 · Assigned by GitHub_M

CVE-2026-34219libp2p-gossipsub: Gossipsub PRUNE Backoff Heartbeat Instant Overflow

High 8.2

In plain English

A high-severity integer overflow in rust-libp2p from libp2p. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities).

Severity (CVSS 4.0)8.2High

Exploit odds (30 days)0.6%top 51.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 (as reported)

Vendor	Product	Versions
libp2p	rust-libp2p	< 0.49.4

Weakness: CWE-190, CWE-617 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References

https://github.com/libp2p/rust-libp2p/security/advisories/GHSA-xqmp-fxgv-xvq5 x_refsource_CONFIRM