{"cve":"CVE-2020-26302","nvd":{"published":"2022-12-22T21:15:08.877","modified":"2026-06-17T03:08:02.120","status":"Modified","description":"is.js is a general-purpose check library. Versions 0.9.0 and prior contain one or more regular expressions that are vulnerable to Regular Expression Denial of Service (ReDoS). is.js uses a regex copy-pasted from a gist to validate URLs. Trying to validate a malicious string can cause the regex to loop “forever.\" This vulnerability was found using a CodeQL query which identifies inefficient regular expressions. is.js has no patch for this issue.","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-1333","CWE-400"],"references":["https://github.com/arasatasaygin/is.js/issues/320","https://securitylab.github.com/advisories/GHSL-2020-295-redos-is.js","https://github.com/arasatasaygin/is.js/issues/320","https://securitylab.github.com/advisories/GHSL-2020-295-redos-is.js"],"products":["is.js_project:is.js"],"source":"nvd","synced_at":"2026-10-19T21:37:31.370122805+00:00"},"epss":{"cve":"CVE-2020-26302","score":0.00924,"percentile":0.60443,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-pvrw-g6fx-mcx2","url":"https://osv.dev/vulnerability/GHSA-pvrw-g6fx-mcx2","summary":"is_js vulnerable to Regular Expression Denial of Service","modified":"2023-11-08T04:03:18.759304Z","packages":[{"ecosystem":"npm","name":"is_js","purl":"pkg:npm/is_js","ranges":["<=0.9.0"],"fixed":[]}]}],"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."]}