{"cve":"CVE-2019-25220","nvd":{"published":"2024-11-18T04:15:04.107","modified":"2026-06-17T02:31:46.793","status":"Analyzed","description":"Bitcoin Core before 24.0.1 allows remote attackers to cause a denial of service (daemon crash) via a flood of low-difficulty header chains (aka a \"Chain Width Expansion\" attack) because a node does not first verify that a presented chain has enough work before committing to store it.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-770"],"references":["https://bitcoincore.org/en/2024/09/18/disclose-headers-oom","https://en.bitcoin.it/wiki/Common_Vulnerabilities_and_Exposures","https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-October/017354.html"],"products":["bitcoin:bitcoin_core"],"source":"nvd","synced_at":"2026-10-19T21:57:34.731061660+00:00"},"epss":{"cve":"CVE-2019-25220","score":0.00817,"percentile":0.57127,"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."]}