CVE-2026-34219

// Conceptual Rust PoC demonstrating the logic flaw // This simulates the handling of a malicious PRUNE message leading to overflow. use std::time::{Duration, Instant}; fn main() { // 1. Attacker sends a PRUNE message with a backoff value near Instant::MAX // For demonstration, we simulate the stored value directly. let near_max_backoff = Instant::now() + Duration::from_secs(315360000000); // Far future // 2. Vulnerable code logic in heartbeat processing // The code attempts to add 'slack' to the stored backoff time let slack = Duration::from_secs(60); // This operation causes an arithmetic overflow in Rust // triggering a thread panic. let result = near_max_backoff.checked_add(slack); match result { Some(time) => println!("Next attempt at: {:?}", time), None => { // In the vulnerable version, simple '+' is used causing panic. // panic!("overflow when adding duration to instant"); println!("Simulated Overflow: The vulnerable code would panic here."); } } }

{"cve": {"id": "CVE-2026-34219", "sourceIdentifier": "[email protected]", "published": "2026-03-31T16:16:31.920", "lastModified": "2026-05-01T18:37:33.773", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 8.2, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.2, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-190"}, {"lang": "en", "value": "CWE-617"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:protocol:libp2p-gossipsub:*:*:*:*:*:rust:*:*", "versionEndExcluding": "0.49.4", "matchCriteriaId": "009FD6F7-1ED8-440F-8394-3BCA41D1C0E9"}]}]}], "references": [{"url": "https://github.com/libp2p/rust-libp2p/security/advisories/GHSA-xqmp-fxgv-xvq5", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}]}}