{"cve":"CVE-2026-86038","nvd":{"published":"2026-09-17T16:18:16.927","modified":"2026-09-30T17:51:36.337","status":"Awaiting Analysis","description":"libp2p is a JavaScript implementation of the libp2p networking stack. From 15.0.0 until 16.0.5, @libp2p/gossipsub uses the default StrictSign policy in packages/gossipsub/src/utils/buildRawMessage.ts, where validateToRawMessage verifies a signature with attacker-controlled msg.key but skips binding that key to msg.from when the claimed author is an RSA peer ID that does not inline a public key. An unauthenticated attacker can place a victim RSA peer ID in msg.from, sign the message with the attacker's private key, and supply the attacker's public key in msg.key, causing the message to be accepted and propagated as authored by the victim. Applications that trust message.from for validators, authorization, accounting, moderation, reputation, or audit logging can process attacker-controlled data under false origin attribution. The issue is fixed in version 16.0.5.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-345","CWE-347"],"references":["https://github.com/libp2p/js-libp2p/commit/cec2b1f349d130065e561349a0336a239528267f","https://github.com/libp2p/js-libp2p/pull/3569","https://github.com/libp2p/js-libp2p/releases/tag/gossipsub-v16.0.5","https://github.com/libp2p/js-libp2p/security/advisories/GHSA-c3gv-825q-fvmp","https://github.com/libp2p/js-libp2p/security/advisories/GHSA-c3gv-825q-fvmp"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:55:23.253742848+00:00"},"epss":{"cve":"CVE-2026-86038","score":0.00193,"percentile":0.08826,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-c3gv-825q-fvmp","url":"https://osv.dev/vulnerability/GHSA-c3gv-825q-fvmp","summary":"libp2p: Gossipsub StrictSign accepts attacker-signed messages as a victim RSA peer ID","modified":"2026-09-17T17:45:04.131264619Z","packages":[{"ecosystem":"npm","name":"@libp2p/gossipsub","purl":"pkg:npm/%40libp2p/gossipsub","ranges":[">=15.0.0 <16.0.5"],"fixed":["16.0.5"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}