{"id":"GHSA-h6q6-9hqw-rwfv","summary":"Misinterpretation of malicious XML input","details":"### Impact\n\nxmldom versions 0.4.0 and older do not correctly preserve [system identifiers](https://www.w3.org/TR/2008/REC-xml-20081126/#d0e4313), [FPIs](https://en.wikipedia.org/wiki/Formal_Public_Identifier) or [namespaces](https://www.w3.org/TR/xml-names11/) when repeatedly parsing and serializing maliciously crafted documents.\n\nThis may lead to unexpected syntactic changes during XML processing in some downstream applications.\n\n### Patches\n\nUpdate to 0.5.0 (once it is released)\n\n### Workarounds\n\nDownstream applications can validate the input and reject the maliciously crafted documents.\n\n### References\n\nSimilar to this one reported on the Go standard library:\n\n- https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities/\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\n* Open an issue in [`xmldom/xmldom`](https://github.com/xmldom/xmldom)\n* Email us: send an email to **all** addresses that are shown by `npm owner ls xmldom`","aliases":["CVE-2021-21366"],"modified":"2026-07-08T06:26:59.943693799Z","published":"2021-03-12T22:39:39Z","related":["CGA-rpfj-2ggx-58h7"],"database_specific":{"github_reviewed":true,"nvd_published_at":"2021-03-12T17:15:00Z","severity":"MODERATE","cwe_ids":["CWE-115","CWE-436"],"github_reviewed_at":"2021-03-12T16:21:24Z"},"references":[{"type":"WEB","url":"https://github.com/xmldom/xmldom/security/advisories/GHSA-h6q6-9hqw-rwfv"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21366"},{"type":"WEB","url":"https://github.com/xmldom/xmldom/commit/d4201b9dfbf760049f457f9f08a3888d48835135"},{"type":"PACKAGE","url":"https://github.com/xmldom/xmldom"},{"type":"WEB","url":"https://github.com/xmldom/xmldom/releases/tag/0.5.0"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2023/01/msg00000.html"},{"type":"WEB","url":"https://www.npmjs.com/package/xmldom"}],"affected":[{"package":{"name":"xmldom","ecosystem":"npm","purl":"pkg:npm/xmldom"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.5.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/03/GHSA-h6q6-9hqw-rwfv/GHSA-h6q6-9hqw-rwfv.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N"}]}