{"id":"CVE-2023-23556","aliases":["EUVD-2023-27656","GHSA-5wwx-r37w-hqhw"],"status":"published","title":"An error in BigInt conversion to Number in Hermes prior to commit...","description":"An error in BigInt conversion to Number in Hermes prior to commit a6dcafe6ded8e61658b40f5699878cd19a481f80 could have been used by a malicious attacker to execute arbitrary code due to an out-of-bound write. Note that this bug is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.00891,"percentile":0.59839,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-787"],"published":"2023-05-18T21:16:43Z","modified":"2026-10-31T07:05:23Z","products":[{"vendor":"facebook","product":"hermes"},{"vendor":"softwarepub","product":"hermes"}],"references":[{"url":"https://www.facebook.com/security/advisories/cve-2023-23556","tags":["x_refsource_CONFIRM","x_transferred","Patch","Vendor Advisory","advisory"]},{"url":"https://github.com/facebook/hermes/commit/a6dcafe6ded8e61658b40f5699878cd19a481f80","tags":["x_refsource_MISC","x_transferred","Patch","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-23556","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-5wwx-r37w-hqhw"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/23xxx/CVE-2023-23556.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2023-23556","description":"An error in BigInt conversion to Number in Hermes prior to commit a6dcafe6ded8e61658b40f5699878cd19a481f80 could have been used by a malicious attacker to execute arbitrary code due to an out-of-bound write. Note that this bug is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.","status":"published","published":"2023-05-18T21:16:43.874Z","modified":"2025-01-31T13:49:25.972Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"adp"}],"updated_at":"2026-11-02T14:35:20.812737Z"}],"euvd":[{"id":"EUVD-2023-27656","description":"An error in BigInt conversion to Number in Hermes prior to commit a6dcafe6ded8e61658b40f5699878cd19a481f80 could have been used by a malicious attacker to execute arbitrary code due to an out-of-bound write. Note that this bug is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.","status":"published","published":"2023-05-18T21:16:43Z","modified":"2025-01-31T13:49:25Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-03T00:04:08.578338Z"}],"ghsa":[{"id":"GHSA-5wwx-r37w-hqhw","title":"An error in BigInt conversion to Number in Hermes prior to commit...","description":"An error in BigInt conversion to Number in Hermes prior to commit a6dcafe6ded8e61658b40f5699878cd19a481f80 could have been used by a malicious attacker to execute arbitrary code due to an out-of-bound write. Note that this bug is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.","status":"published","published":"2023-05-19T00:30:18Z","modified":"2024-04-04T04:14:44Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:56:22.389253Z"}],"nvd":[{"id":"CVE-2023-23556","description":"An error in BigInt conversion to Number in Hermes prior to commit a6dcafe6ded8e61658b40f5699878cd19a481f80 could have been used by a malicious attacker to execute arbitrary code due to an out-of-bound write. Note that this bug is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.","status":"published","published":"2023-05-18T22:15:09.487Z","modified":"2026-06-17T05:37:25.63Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"secondary"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:08:03.200773Z"}],"osv":[{"id":"CVE-2023-23556","description":"An error in BigInt conversion to Number in Hermes prior to commit a6dcafe6ded8e61658b40f5699878cd19a481f80 could have been used by a malicious attacker to execute arbitrary code due to an out-of-bound write. Note that this bug is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.","status":"published","published":"2023-05-18T21:16:43.874Z","modified":"2026-10-31T07:05:23.503064352Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:44:30.709518Z"}]}}