{"id":"CVE-2018-12556","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-12556","generatedAt":"2026-10-29T02:03:53.111Z","title":"The signature verification routine in install.sh in yarnpkg/website through 2018-06-05 only verifies that the yarn release is signed by any (arbitrary) key in the local keyring of the user, and does not pin the signature to the yarn release key, which…","description":"The signature verification routine in install.sh in yarnpkg/website through 2018-06-05 only verifies that the yarn release is signed by any (arbitrary) key in the local keyring of the user, and does not pin the signature to the yarn release key, which allows remote attackers to sign tampered yarn release packages with their own key.","published":"2019-05-16T17:29:01.000Z","lastModified":"2026-06-17T01:37:58.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.0","score":5.9,"severity":"MEDIUM","vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N"},"cwe":["CWE-347"],"affected":["yarnpkg/website"],"epss":{"score":0.01775,"percentile":0.78085,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (1.77%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://packetstormsecurity.com/files/152703/Johnny-You-Are-Fired.html","tags":["Third Party Advisory","VDB Entry"],"source":"cve@mitre.org"},{"url":"http://seclists.org/fulldisclosure/2019/Apr/38","tags":["Mailing List","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/RUB-NDS/Johnny-You-Are-Fired","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/RUB-NDS/Johnny-You-Are-Fired/blob/master/paper/johnny-fired.pdf","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/yarnpkg/website/commits/master","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.openwall.com/lists/oss-security/2019/04/30/4","tags":["Mailing List","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"http://packetstormsecurity.com/files/152703/Johnny-You-Are-Fired.html","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://seclists.org/fulldisclosure/2019/Apr/38","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/RUB-NDS/Johnny-You-Are-Fired","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/RUB-NDS/Johnny-You-Are-Fired/blob/master/paper/johnny-fired.pdf","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/yarnpkg/website/commits/master","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.openwall.com/lists/oss-security/2019/04/30/4","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-12556","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}