CVE-2026-86039

HIGHPre-NVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 92% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this week
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.2Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
8.2
EG Score
8.2(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity82% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
8%
KEV
Not listed

Published

September 17, 2026

Last Modified

September 17, 2026

Advisory Details (4)

Auto-updated Sep 17, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github, github_pr, github_commit.
github_release Patch Available

peer-store: v12.0.24

Patch available: libp2p/js-libp2p peer-store-v12.0.24

https://github.com/libp2p/js-libp2p/releases/tag/peer-store-v12.0.24
github_commit Patch Available

commit 3bf5d395cbca (libp2p/js-libp2p)

Patch available: libp2p/js-libp2p transport-interop-libp2p-main-v1.0.39 (contains commit 3bf5d395cbca)

https://github.com/libp2p/js-libp2p/commit/3bf5d395cbca1488eea6e87cd771e4613b661c30
github_pr Patch Available

fix: use the same peer id to load and store peer records

Patch available: libp2p/js-libp2p transport-interop-libp2p-main-v1.0.39 (PR #3570 merged 2026-07-17)

https://github.com/libp2p/js-libp2p/pull/3570
github Patch Available🟡 PoC Available

PeerStore accepts attacker-signed PeerRecords for a victim peer ID and stores certified attacker addresses · Advisory · libp2p/js-libp2p · GitHub

https://github.com/libp2p/js-libp2p/security/advisories/GHSA-vrf4-mx87-p53w

Vendor Advisories for CVE-2026-86039(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 6× in last 7d / 6× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 21:20 UTCEG score recompute
  2. 2026-09-18 19:39 UTCEG score recompute
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-17 17:57 UTCEG score recompute
  5. 2026-09-17 15:25 UTCEG score recompute
  6. 2026-09-17 15:24 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-86039?
CVE-2026-86039 is a high vulnerability published on September 17, 2026. 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…
When was CVE-2026-86039 disclosed?
CVE-2026-86039 was first published in the National Vulnerability Database on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-86039 actively exploited?
CVE-2026-86039 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 91.8% of all scored CVEs.
What is the CVSS score of CVE-2026-86039?
CVE-2026-86039 has a CVSS v3 base score of 8.2 (NVD).
How do I remediate CVE-2026-86039?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-86039, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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