{"answers":{"affected":"2 open source packages ship an affected version, including @libp2p/gossipsub.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-86038 exists.","fix":"Upgrade @libp2p/gossipsub to 16.0.5 or later.","what":"CVE-2026-86038 is a high-severity authentication bypass vulnerability in js-libp2p, published on 17 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-86038 and fix it if it is affected.\n\nWhat it is: CVE-2026-86038 is a high-severity authentication bypass vulnerability in js-libp2p, published on 17 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-86038 exists.\n\nAffected packages and fixed versions:\n- @libp2p/gossipsub (npm): affected from 15.0.0; fixed in 16.0.5\n- @libp2p/gossipsub (npm): affected from 15.0.0; fixed in 16.0.5\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-86038/ (Markdown: https://insights.sbomify.com/CVE-2026-86038/index.md)","id":"CVE-2026-86038","markdown":"https://insights.sbomify.com/CVE-2026-86038/index.md","name":"CVE-2026-86038","record":{"aliases":["GHSA-c3gv-825q-fvmp"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["security_bypass","data_modify"],"network_reachable":"yes","non_default_config":false,"product_category":"libp2p JavaScript library","requires_auth":"none","summary":"Attackers can forge message origins in libp2p Gossipsub by bypassing signature validation, leading to false attribution and potential abuse of trust mechanisms.","user_interaction":"not_required","vuln_class":"auth_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-347","name":"Improper Verification of Cryptographic Signature"},{"id":"CWE-345","name":"Insufficient Verification of Data Authenticity"}],"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.","ecosystems":["npm"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"libp2p: Gossipsub StrictSign accepts attacker-signed messages as a victim RSA peer ID","id":"CVE-2026-86038","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"npm","product":null,"products":[],"type":"auth_bypass","year":"2026"},"n_packages":2,"n_references":4,"next":{"headline":"libp2p: PeerStore accepts attacker-signed PeerRecords for a victim peer ID and stores certified attacker addresses","id":"CVE-2026-86039"},"packages":[{"ecosystem":"npm","fixed":["16.0.5"],"introduced":["15.0.0"],"last_affected":[],"package":"@libp2p/gossipsub","purl":null,"source":"GHSA-c3gv-825q-fvmp"},{"ecosystem":"npm","fixed":["16.0.5"],"introduced":["15.0.0"],"last_affected":[],"package":"@libp2p/gossipsub","purl":"pkg:npm/%40libp2p/gossipsub","source":"GHSA-c3gv-825q-fvmp"}],"prev":{"headline":"Weblate: Mercurial argument injection via repository filenames allows authenticated command execution","id":"CVE-2026-86035"},"products":["js-libp2p"],"published":"2026-09-17","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-09-17","vendors":["libp2p"]},"summary":"Attackers can forge message origins in libp2p Gossipsub by bypassing signature validation, leading to false attribution and potential abuse of trust mechanisms.","url":"https://insights.sbomify.com/CVE-2026-86038/"}