Vulnerability · Published Sep 17, 2026 · Assigned by GitHub_M

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

High 8.2

In plain English

A high-severity authentication bypass by spoofing in js-libp2p from libp2p. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 19% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.2High

Exploit odds (30 days)0.3%top 80.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	@libp2p/peer-store	12.0.24	GHSA-vrf4-mx87-p53w

Affected products (as reported)

Vendor	Product	Versions
libp2p	js-libp2p	>= 8.0.0, < 12.0.24

Weakness: CWE-290, CWE-345 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L

References

https://github.com/libp2p/js-libp2p/security/advisories/GHSA-vrf4-mx87-p53w x_refsource_CONFIRM
https://github.com/libp2p/js-libp2p/pull/3570 x_refsource_MISC
https://github.com/libp2p/js-libp2p/commit/3bf5d395cbca1488eea6e87cd771e4613b661c30 x_refsource_MISC
https://github.com/libp2p/js-libp2p/releases/tag/peer-store-v12.0.24 x_refsource_MISC