8.2
HIGH CVSS 3.1
CVE-2026-86039
libp2p: PeerStore accepts attacker-signed PeerRecords for a victim peer ID and stores certified attacker addresses
Description

libp2p is a JavaScript implementation of the libp2p networking stack. From 8.0.0 until 12.0.24, @libp2p/peer-store in packages/peer-store/src/index.ts uses consumePeerRecord to verify a RecordEnvelope signature but does not require PeerRecord.peerId in the signed payload to equal the signer peer ID derived by RecordEnvelope.openAndCertify. The expectedPeer option checks only the envelope signer, and the gossipsub Peer Exchange path can provide the attacker's own peer ID as expectedPeer. An attacker can therefore sign a record with the attacker's key, place a victim peer ID and attacker-controlled multiaddrs in the payload, and have certified addresses stored for the victim. The poisoned addresses can cause address-book corruption, dial redirection or failure, routing manipulation, and reachability disruption, although the connection upgrade still verifies remote peer identity and prevents a complete identity takeover. The issue is fixed in version 12.0.24.

INFO

Published Date :

Sept. 17, 2026, 4:18 p.m.

Last Modified :

Sept. 17, 2026, 4:18 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-86039 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Protocol libp2p
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH MITRE-CVE
CVSS 3.1 HIGH [email protected]
Solution
Update libp2p packages to version 12.0.24 or later to fix peer store vulnerabilities.
  • Update @libp2p/peer-store to 12.0.24 or newer.
  • Verify peer ID and payload integrity.
  • Validate signed record payloads carefully.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-86039 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-86039 weaknesses.

CAPEC-21: Exploitation of Trusted Identifiers Exploitation of Trusted Identifiers CAPEC-22: Exploiting Trust in Client Exploiting Trust in Client CAPEC-59: Session Credential Falsification through Prediction Session Credential Falsification through Prediction CAPEC-60: Reusing Session IDs (aka Session Replay) Reusing Session IDs (aka Session Replay) CAPEC-94: Adversary in the Middle (AiTM) Adversary in the Middle (AiTM) CAPEC-459: Creating a Rogue Certification Authority Certificate Creating a Rogue Certification Authority Certificate CAPEC-461: Web Services API Signature Forgery Leveraging Hash Function Extension Weakness Web Services API Signature Forgery Leveraging Hash Function Extension Weakness CAPEC-473: Signature Spoof Signature Spoof CAPEC-476: Signature Spoofing by Misrepresentation Signature Spoofing by Misrepresentation CAPEC-667: Bluetooth Impersonation AttackS (BIAS) Bluetooth Impersonation AttackS (BIAS) CAPEC-111: JSON Hijacking (aka JavaScript Hijacking) JSON Hijacking (aka JavaScript Hijacking) CAPEC-141: Cache Poisoning Cache Poisoning CAPEC-142: DNS Cache Poisoning DNS Cache Poisoning CAPEC-148: Content Spoofing Content Spoofing CAPEC-218: Spoofing of UDDI/ebXML Messages Spoofing of UDDI/ebXML Messages CAPEC-384: Application API Message Manipulation via Man-in-the-Middle Application API Message Manipulation via Man-in-the-Middle CAPEC-385: Transaction or Event Tampering via Application API Manipulation Transaction or Event Tampering via Application API Manipulation CAPEC-386: Application API Navigation Remapping Application API Navigation Remapping CAPEC-387: Navigation Remapping To Propagate Malicious Content Navigation Remapping To Propagate Malicious Content CAPEC-388: Application API Button Hijacking Application API Button Hijacking CAPEC-665: Exploitation of Thunderbolt Protection Flaws Exploitation of Thunderbolt Protection Flaws CAPEC-701: Browser in the Middle (BiTM) Browser in the Middle (BiTM)

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-86039 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-86039 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 17, 2026

    Action Type Old Value New Value
    Added Description libp2p is a JavaScript implementation of the libp2p networking stack. From 8.0.0 until 12.0.24, @libp2p/peer-store in packages/peer-store/src/index.ts uses consumePeerRecord to verify a RecordEnvelope signature but does not require PeerRecord.peerId in the signed payload to equal the signer peer ID derived by RecordEnvelope.openAndCertify. The expectedPeer option checks only the envelope signer, and the gossipsub Peer Exchange path can provide the attacker's own peer ID as expectedPeer. An attacker can therefore sign a record with the attacker's key, place a victim peer ID and attacker-controlled multiaddrs in the payload, and have certified addresses stored for the victim. The poisoned addresses can cause address-book corruption, dial redirection or failure, routing manipulation, and reachability disruption, although the connection upgrade still verifies remote peer identity and prevents a complete identity takeover. The issue is fixed in version 12.0.24.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
    Added CWE CWE-345
    Added CWE CWE-290
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/86xxx/CVE-2026-86039.json">CVE-2026-86039</a>
    Added Reference https://github.com/libp2p/js-libp2p/commit/3bf5d395cbca1488eea6e87cd771e4613b661c30
    Added Reference https://github.com/libp2p/js-libp2p/pull/3570
    Added Reference https://github.com/libp2p/js-libp2p/releases/tag/peer-store-v12.0.24
    Added Reference https://github.com/libp2p/js-libp2p/security/advisories/GHSA-vrf4-mx87-p53w
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.