{"cve":"CVE-2023-23557","nvd":{"published":"2023-05-18T22:15:09.540","modified":"2026-06-17T05:37:25.843","status":"Modified","description":"An error in Hermes' algorithm for copying objects properties prior to commit a00d237346894c6067a594983be6634f4168c9ad could be used by a malicious attacker to execute arbitrary code via type confusion. Note that this is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-843"],"references":["https://github.com/facebook/hermes/commit/a00d237346894c6067a594983be6634f4168c9ad","https://www.facebook.com/security/advisories/cve-2023-23557","https://github.com/facebook/hermes/commit/a00d237346894c6067a594983be6634f4168c9ad","https://www.facebook.com/security/advisories/cve-2023-23557"],"products":["facebook:hermes"],"source":"nvd","synced_at":"2026-10-19T21:38:18.424950729+00:00"},"epss":{"cve":"CVE-2023-23557","score":0.00891,"percentile":0.5942,"date":"2026-10-31"},"kev":null,"osv":[],"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."]}