# CVE-2026-95859: libp2p-rust Gossipsub GRAFT memory exhaustion DoS

Source: https://junglewise.ai/threats/cve-2026-95859-libp2p-rust-is-the-official-rust-language-implementation-of-the  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-16. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-95859 · Severity: info · Published 2026-10-16

libp2p-rust is a peer-to-peer networking library used in blockchain and decentralized applications. An attacker can send crafted network messages to cause unbounded memory consumption, crashing applications that rely on this library and disrupting services that depend on it.

Vendors: [Libp2p](https://junglewise.ai/threats/vendors/libp2p).

## Quick answers

**Is CVE-2026-95859 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-95859 being exploited in the wild.

**How severe is CVE-2026-95859?** Informational severity, published 16 October 2026.

**Which products and versions are affected?** Libp2p Rust-Libp2p prior to 0.49.5.

**Is there a fix for CVE-2026-95859?** Yes: fixed in 0.49.5. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-95859 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-95859?** Check whether you run Libp2p Rust-Libp2p at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 0.49.5

## Technical details

The Gossipsub protocol handler in libp2p-rust versions prior to 0.49.5 unconditionally adds attacker-supplied topic hashes to the connected_peer.topics map without validating prior subscription. A remote unauthenticated peer can send repeated GRAFT control messages with novel topic hashes, causing cumulative per-peer memory growth that bypasses subscription filters and peer scoring limits, leading to process memory exhaustion.

## Affected products

- libp2p rust-libp2p prior to 0.49.5

## Timeline

- 2026-10-16: disclosed
- 2026-09-05: patched

## References

- [https://github.com/libp2p/rust-libp2p/commit/51ed5f00e1b0620ded3444ecadf18477052148ea](https://github.com/libp2p/rust-libp2p/commit/51ed5f00e1b0620ded3444ecadf18477052148ea)
- [https://github.com/libp2p/rust-libp2p/pull/6608](https://github.com/libp2p/rust-libp2p/pull/6608)