# CVE-2026-34219

## Summary

- **CVE ID:** CVE-2026-34219
- **Severity:** HIGH
- **CVSS Score:** 8.2 (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)
- **CWE:** CWE-190, CWE-617
- **Published:** Mar 31, 2026
- **Last Modified:** Mar 31, 2026

## 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

- libp2p — rust-libp2p (< 0.49.4)

## References

- [CNA](https://github.com/libp2p/rust-libp2p/security/advisories/GHSA-xqmp-fxgv-xvq5)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.56%
- **EPSS Percentile:** 44.8

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._