Vulnerability · Published Oct 16, 2026 · Assigned by GitHub_M

CVE-2026-95859libp2p-rust: Gossipsub GRAFT topics unbounded growth

High 8.7

In plain English

A high-severity resource allocation without limits 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 0.3% (higher than 22% of all known vulnerabilities).

Severity (CVSS 4.0)8.7High

Exploit odds (30 days)0.3%top 78.2% 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 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.

Affected products (as reported)

Vendor	Product	Versions
libp2p	rust-libp2p	< 0.49.5

Weakness: CWE-770 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/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-g3g5-x568-qvqx x_refsource_CONFIRM
https://github.com/libp2p/rust-libp2p/pull/6608 x_refsource_MISC
https://github.com/libp2p/rust-libp2p/commit/51ed5f00e1b0620ded3444ecadf18477052148ea x_refsource_MISC