{"id":"CVE-2020-1911","url":"https://www.cyber-defence.io/tools/cve/CVE-2020-1911","generatedAt":"2026-10-27T22:26:21.194Z","title":"A type confusion vulnerability when resolving properties of JavaScript objects with specially-crafted prototype chains in Facebook Hermes prior to commit fe52854cdf6725c2eaa9e125995da76e6ceb27da allows attackers to potentially execute arbitrary code via…","description":"A type confusion vulnerability when resolving properties of JavaScript objects with specially-crafted prototype chains in Facebook Hermes prior to commit fe52854cdf6725c2eaa9e125995da76e6ceb27da allows attackers to potentially execute arbitrary code via crafted JavaScript. Note that this is only exploitable if the application using Hermes permits evaluation of untrusted JavaScript. Hence, most React Native applications are not affected.","published":"2020-09-04T03:15:10.000Z","lastModified":"2026-06-17T03:02:36.000Z","status":"Modified","sourceIdentifier":"cve-assign@fb.com","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-843"],"affected":["facebook/hermes"],"epss":{"score":0.02003,"percentile":0.80652,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (2.00%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/facebook/hermes/commit/fe52854cdf6725c2eaa9e125995da76e6ceb27da","tags":["Patch","Third Party Advisory"],"source":"cve-assign@fb.com"},{"url":"https://www.facebook.com/security/advisories/cve-2020-1911","tags":["Third Party Advisory"],"source":"cve-assign@fb.com"},{"url":"https://github.com/facebook/hermes/commit/fe52854cdf6725c2eaa9e125995da76e6ceb27da","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.facebook.com/security/advisories/cve-2020-1911","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2020-1911","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."}