{"cve":"CVE-2018-20164","nvd":{"published":"2019-02-13T14:29:00.240","modified":"2026-06-17T01:52:22.617","status":"Modified","description":"An issue was discovered in regex.yaml (aka regexes.yaml) in UA-Parser UAP-Core before 0.6.0. A Regular Expression Denial of Service (ReDoS) issue allows remote attackers to overload a server by setting the User-Agent header in an HTTP(S) request to a value containing a long digit string. (The UAP-Core project contains the vulnerability, propagating to all implementations.)","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","score":5.3},"cwes":["CWE-185"],"references":["https://github.com/ua-parser/uap-core/commit/010ccdc7303546cd22b9da687c29f4a996990014","https://github.com/ua-parser/uap-core/commit/156f7e12b215bddbaf3df4514c399d683e6cdadc","https://github.com/ua-parser/uap-core/issues/332","https://www.x41-dsec.de/lab/advisories/x41-2018-009-uaparser/","https://github.com/ua-parser/uap-core/commit/010ccdc7303546cd22b9da687c29f4a996990014"],"products":["uaparser:user_agent_parser-core"],"source":"nvd","synced_at":"2026-10-19T20:54:46.948512734+00:00"},"epss":{"cve":"CVE-2018-20164","score":0.03298,"percentile":0.88515,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-fx7m-j728-mjw3","url":"https://osv.dev/vulnerability/GHSA-fx7m-j728-mjw3","summary":"uap-core Regular Expression Denial of Service issue","modified":"2023-11-08T04:00:11.152642Z","packages":[{"ecosystem":"npm","name":"uap-core","purl":"pkg:npm/uap-core","ranges":["<0.6.0"],"fixed":["0.6.0"]}]}],"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."]}