CVE-2026-95859 libp2p-rust: Gossipsub GRAFT topics unbounded growth
Remote attackers can cause memory exhaustion and denial of service in libp2p-rust by sending unbounded GRAFT topics.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-95859?
CVE-2026-95859 is a high-severity denial of service vulnerability in rust-libp2p, published on 16 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
libp2p-rust is the official Rust language implementation of the libp2p networking stack. Prior to 0.49.5, Gossipsub GRAFT control-message handling unconditionally adds attacker-supplied topic hashes to connected_peer.topics without confirming that the peer previously subscribed to those topics. A remote unauthenticated peer that can reach a Gossipsub listener can repeatedly send novel GRAFT topics, causing cumulative per-peer memory growth that is not bounded by subscription filters, peer scoring, or per-message size limits. This can exhaust process memory and cause a denial of service. This issue is fixed in version 0.49.5.
Weakness: CWE-770
Which versions are affected by CVE-2026-95859?
How do I fix CVE-2026-95859?
No fix has been published for CVE-2026-95859 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-95859 being exploited?
There is no known exploitation of CVE-2026-95859 in the wild and no public exploit code.
Sources
Also known as GHSA-g3g5-x568-qvqx.