{"id":"CVE-2026-73569","aliases":["GHSA-8r6m-32jq-jx6q"],"url":"https://o3.security/vulnerability/CVE-2026-73569","summary":"fast-xml-parser: Repeated DOCTYPE declarations reset entity expansion limits","details":"### Impact\n`fast-xml-parser` processes multiple \"DOCTYPE\" declarations within a single XML document. Each declaration passes its entities to `@nodable/entities` through `addInputEntities()`.\n\n`addInputEntities()` resets the entity expansion counters every time it is called. An attacker can therefore insert additional DOCTYPE declarations to repeatedly reset maxTotalExpansions and maxExpandedLength during one parse operation.\n\nThis allows a crafted XML document to exceed the configured entity-expansion limits and can cause excessive CPU use, event-loop blocking, memory exhaustion, and process termination.\n\n### Workarounds\n- Manually check if multiple DOCTYPEs are not present in input contents\n- Update to v5.10.1\n- Keep `processEntity` flag off","published":"2026-08-13T17:45:25.045Z","modified":"2026-09-20T11:47:27.599233687Z","cvss":null,"epss":{"score":0.00372,"percentile":0.30675,"asOf":"2026-09-15"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"fast-xml-parser","fixedVersion":"5.10.1"}],"fix":{"url":"https://github.com/NaturalIntelligence/fast-xml-parser/commit/4e546e03987662de5495d050b5fba26bea65383f","label":"NaturalIntelligence/fast-xml-parser@4e546e0"},"references":[{"type":"WEB","url":"https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.10.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73569.json"},{"type":"ADVISORY","url":"https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-8r6m-32jq-jx6q"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-73569"},{"type":"FIX","url":"https://github.com/NaturalIntelligence/fast-xml-parser/commit/4e546e03987662de5495d050b5fba26bea65383f"},{"type":"PACKAGE","url":"https://github.com/NaturalIntelligence/fast-xml-parser"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-20T11:47:27.599233687Z"}}