{"cve":"CVE-2021-21366","nvd":{"published":"2021-03-12T17:15:12.643","modified":"2026-06-17T03:35:24.040","status":"Modified","description":"xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. xmldom versions 0.4.0 and older do not correctly preserve system identifiers, FPIs or namespaces when repeatedly parsing and serializing maliciously crafted documents. This may lead to unexpected syntactic changes during XML processing in some downstream applications. This is fixed in version 0.5.0. As a workaround downstream applications can validate the input and reject the maliciously crafted documents.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N","score":4.3},"cwes":["CWE-436","CWE-115"],"references":["https://github.com/xmldom/xmldom/commit/d4201b9dfbf760049f457f9f08a3888d48835135","https://github.com/xmldom/xmldom/releases/tag/0.5.0","https://github.com/xmldom/xmldom/security/advisories/GHSA-h6q6-9hqw-rwfv","https://lists.debian.org/debian-lts-announce/2023/01/msg00000.html","https://www.npmjs.com/package/xmldom"],"products":["debian:debian_linux","xmldom_project:xmldom"],"source":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-21366","score":0.0134,"percentile":0.71308,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-h6q6-9hqw-rwfv","url":"https://osv.dev/vulnerability/GHSA-h6q6-9hqw-rwfv","summary":"Misinterpretation of malicious XML input","modified":"2026-09-10T03:49:02.254678560Z","packages":[{"ecosystem":"npm","name":"xmldom","purl":"pkg:npm/xmldom","ranges":["<0.5.0"],"fixed":["0.5.0"]}]}],"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."]}