{"id":"CVE-2026-33036","summary":"fast-xml-parser affected by numeric entity expansion bypassing all entity expansion limits (incomplete fix for CVE-2026-26278)","details":"fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. Versions 4.0.0-beta.3 through 5.5.5 contain a bypass vulnerability where numeric character references (&#NNN;, &#xHH;) and standard XML entities completely evade the entity expansion limits (e.g., maxTotalExpansions, maxExpandedLength) added to fix CVE-2026-26278, enabling XML entity expansion Denial of Service. The root cause is that replaceEntitiesValue() in OrderedObjParser.js only enforces expansion counting on DOCTYPE-defined entities while the lastEntities loop handling numeric/standard entities performs no counting at all. An attacker supplying 1M numeric entity references like A can force ~147MB of memory allocation and heavy CPU usage, potentially crashing the process—even when developers have configured strict limits. This issue has been fixed in version 5.5.6.","aliases":["GHSA-8gc5-j5rx-235r"],"modified":"2026-03-31T17:29:41.377945048Z","published":"2026-03-20T05:17:03.290Z","related":["CGA-39jr-ffp7-cmcf","openSUSE-SU-2026:10462-1"],"database_specific":{"cwe_ids":["CWE-776"],"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33036.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33036.json"},{"type":"FIX","url":"https://github.com/NaturalIntelligence/fast-xml-parser/commit/bd26122c838e6a55e7d7ac49b4ccc01a49999a01"},{"type":"WEB","url":"https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.5.6"},{"type":"ADVISORY","url":"https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-8gc5-j5rx-235r"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33036"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/naturalintelligence/fast-xml-parser","events":[{"introduced":"7439272f2a98f8a551de7a105faeab58c6fbf74a"},{"fixed":"870043e75e78545192bc70950c6286d36c7cdf23"}],"database_specific":{"versions":[{"introduced":"4.0.0-beta.3"},{"fixed":"5.5.6"}]}}],"versions":["4.2.1","4.2.2","v4.0.0","v4.0.0-beta.3","v4.0.0-beta.4","v4.0.0-beta.5","v4.0.0-beta.6","v4.0.0-beta.7","v4.0.0-beta.8","v4.0.1","v4.0.10","v4.0.11","v4.0.12","v4.0.13","v4.0.14","v4.0.15","v4.0.2","v4.0.3","v4.0.4","v4.0.5","v4.0.6","v4.0.7","v4.0.8","v4.0.9","v4.1.0","v4.1.1","v4.1.2","v4.1.3","v4.1.4","v4.2.0","v4.2.3","v4.2.4","v4.2.5","v4.2.6","v4.2.7","v4.3.0","v4.3.1","v4.3.2","v4.3.3","v4.3.4","v4.3.5","v4.3.6","v4.4.0","v4.4.1","v4.5.0","v4.5.1","v4.5.2","v4.5.3","v4.5.4","v4.5.4x","v4.5.5","v5.0.0","v5.0.1","v5.0.2","v5.0.3","v5.0.4","v5.0.5","v5.0.6","v5.0.7","v5.0.8","v5.0.9","v5.1.0","v5.2.0","v5.2.1","v5.2.2","v5.2.3","v5.2.4","v5.2.5","v5.3.0","v5.3.1","v5.3.2","v5.3.3","v5.3.4","v5.3.5","v5.3.6","v5.3.7","v5.3.8","v5.3.9","v5.4.0","v5.4.1","v5.4.2","v5.5.0","v5.5.1","v5.5.2","v5.5.3","v5.5.4","v5.5.5"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-33036.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}