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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.2 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L

EPSS

• CVE-2026-86039: 0.27% estimated exploitation activity in the next 30 days; percentile 19.20 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary @libp2p/peer-store accepts a signed PeerRecord whose envelope is signed by one peer but whose payload claims a different peer ID. The vulnerable consumePeerRecord path verifies the envelope signature, but does not verify that the envelope signer is the same peer as the wrapped PeerRecord.peerId. As a result, an attacker can sign a record with their own key while placing a victim peer ID in the payload, causing attacker-controlled multiaddrs to be stored as certified addresses for the victim. Details The vulnerable code is in packages/peer-store/src/index.ts: - RecordEnvelope.openAndCertify(buf, PeerRecord.DOMAIN, options) verifies the envelope signature. - const peerId = peerIdFromCID(envelope.publicKey.toCID()) derives the envelope signer peer ID. - The optional expectedPeer check only compares expectedPeer to the envelope signer. - const peerRecord = PeerRecord.createFromProtobuf(envelope.payload) decodes peerRecord.peerId from attacker-controlled signed payload bytes. -…

Published by the source

17 Sep 2026, 18:01 UTC

Last modified by the source

17 Sep 2026, 18:15 UTC

Source last checked

26 Oct 2026, 13:02 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-vrf4-mx87-p53w

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-vrf4-mx87-p53w

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-vrf4-mx87-p53w

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# Patch Next advisory brief: CVE-2026-86039

Advisory: libp2p: PeerStore accepts attacker-signed PeerRecords for a victim peer ID and stores certified attacker addresses
IDs: CVE-2026-86039, GHSA-vrf4-mx87-p53w
Record: https://patchnext.com/advisories/cve-2026-86039 (revision 3, source checked 26 Oct 2026, 13:02 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @libp2p/peer-store 12.0.24. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @libp2p/peer-store: affected >= 8.0.0, < 12.0.24; fixed in 12.0.24

## Suggested inspection (read-only)
- `npm ls @libp2p/peer-store --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @libp2p/peer-store.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-vrf4-mx87-p53w (GitHub-reviewed advisory GHSA-vrf4-mx87-p53w lists affected ranges: npm @libp2p/peer-store >=8.0.0 <12.0.24)
- Verified: https://osv.dev/vulnerability/GHSA-vrf4-mx87-p53w (OSV record GHSA-vrf4-mx87-p53w lists affected ranges: npm @libp2p/peer-store >=8.0.0 <12.0.24 (fixed))

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