{"answers":{"affected":"4 open source packages ship an affected version, including fast-xml-parser. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33036 exists.","fix":"Upgrade fast-xml-parser to a fixed version for your release line: 4.5.5 or 5.5.6.","what":"CVE-2026-33036 is a high-severity denial of service vulnerability in NaturalIntelligence fast-xml-parser, published on 20 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-33036 and fix it if it is affected.\n\nWhat it is: CVE-2026-33036 is a high-severity denial of service vulnerability in NaturalIntelligence fast-xml-parser, published on 20 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33036 exists.\n\nAffected packages and fixed versions:\n- fast-xml-parser (npm): affected from 4.0.0-beta.3; fixed in 4.5.5\n- fast-xml-parser (npm): affected from 4.0.0-beta.3; fixed in 4.5.5\n- fast-xml-parser (npm): affected from 5.0.0; fixed in 5.5.6\n- fast-xml-parser (npm): affected from 5.0.0; fixed in 5.5.6\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-33036/ (Markdown: https://insights.sbomify.com/CVE-2026-33036/index.md)","id":"CVE-2026-33036","markdown":"https://insights.sbomify.com/CVE-2026-33036/index.md","name":"CVE-2026-33036","record":{"aliases":["CLEANSTART-2026-DN87303","CLEANSTART-2026-HQ50857","CLSA-2026-1790005086","DEBIAN-CVE-2026-33036","ECHO-d6a2-ff98-f3bf","GHSA-8gc5-j5rx-235r","MINI-23hw-qf3p-v2c9","MINI-2fcp-347x-h28q","MINI-447h-x75q-3vwf","MINI-565x-vhhm-459h","MINI-5f5w-qjcv-8452","MINI-648p-h398-4cp8","MINI-64qx-p4fv-47v7","MINI-94j4-mrqj-7x7h","MINI-f3f8-q457-g4rr","MINI-m2rq-8h9r-p47g","MINI-mfmv-rv83-4h42","MINI-mvxc-w3rv-685m","MINI-p7wc-9hpp-4jmm","MINI-r5rw-x3mc-hwp2","MINI-rxqm-ffj3-fgrj","MINI-vxmp-rmx3-6jfg","ROOT-APP-NPM-CVE-2026-33036","UBUNTU-CVE-2026-33036","openSUSE-SU-2026:10462-1"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"JavaScript XML parser","requires_auth":"none","summary":"An attacker can cause denial of service in fast-xml-parser by using numeric entity references that bypass expansion limits, leading to excessive memory and CPU usage.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"fast-xml-parser","vendor":"naturalintelligence"}],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-776","name":"Improper Restriction of Recursive Entity References in DTDs"}],"description":"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 (\u0026#NNN;, \u0026#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 \u0026#65; 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.","ecosystems":["npm","openSUSE:Tumbleweed"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"fast-xml-parser affected by numeric entity expansion bypassing all entity expansion limits (incomplete fix for CVE-2026-26278)","id":"CVE-2026-33036","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"npm","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":5,"n_references":3,"next":{"headline":"WWBN AVideo has predictable default admin credentials in official Docker deployment path","id":"CVE-2026-33037"},"packages":[{"ecosystem":"npm","fixed":["4.5.5"],"introduced":["4.0.0-beta.3"],"last_affected":[],"package":"fast-xml-parser","purl":null,"source":"GHSA-8gc5-j5rx-235r"},{"ecosystem":"npm","fixed":["4.5.5"],"introduced":["4.0.0-beta.3"],"last_affected":[],"package":"fast-xml-parser","purl":"pkg:npm/fast-xml-parser","source":"GHSA-8gc5-j5rx-235r"},{"ecosystem":"npm","fixed":["5.5.6"],"introduced":["5.0.0"],"last_affected":[],"package":"fast-xml-parser","purl":null,"source":"GHSA-8gc5-j5rx-235r"},{"ecosystem":"npm","fixed":["5.5.6"],"introduced":["5.0.0"],"last_affected":[],"package":"fast-xml-parser","purl":"pkg:npm/fast-xml-parser","source":"GHSA-8gc5-j5rx-235r"},{"ecosystem":"openSUSE:Tumbleweed","fixed":["2.20.1-4.1"],"introduced":["0"],"last_affected":[],"package":"heroic-games-launcher","purl":"pkg:rpm/opensuse/heroic-games-launcher\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2026:10462-1"}],"prev":{"headline":"Unauthenticated Reflected XSS via innerHTML in AVideo","id":"CVE-2026-33035"},"products":["fast-xml-parser"],"published":"2026-03-20","related":[{"cvss_score":9.3,"headline":"fast-xml-parser has an entity encoding bypass via regex injection in DOCTYPE entity names","id":"CVE-2026-25896","kev_date_added":null,"published":"2026-02-20"},{"cvss_score":7.5,"headline":"fast-xml-parser affected by DoS through entity expansion in DOCTYPE (no expansion limit)","id":"CVE-2026-26278","kev_date_added":null,"published":"2026-02-19"},{"cvss_score":7.5,"headline":"fast-xml-parser has RangeError DoS Numeric Entities Bug","id":"CVE-2026-25128","kev_date_added":null,"published":"2026-01-30"},{"cvss_score":7.5,"headline":"ReDOS at currency parsing fast-xml-parser","id":"CVE-2024-41818","kev_date_added":null,"published":"2024-07-29"},{"cvss_score":7.5,"headline":"Regex Injection via Doctype Entities","id":"CVE-2023-34104","kev_date_added":null,"published":"2023-06-06"},{"cvss_score":6.1,"headline":"fast-xml-parser XMLBuilder: XML Comment and CDATA Injection via Unescaped Delimiters","id":"CVE-2026-41650","kev_date_added":null,"published":"2026-05-07"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"SUSE","prefix":"openSUSE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-03-25","vendors":["NaturalIntelligence"]},"summary":"An attacker can cause denial of service in fast-xml-parser by using numeric entity references that bypass expansion limits, leading to excessive memory and CPU usage.","url":"https://insights.sbomify.com/CVE-2026-33036/"}