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7.5 High

CVE-2023-34104 fast-xml-parser is an open source, pure javascript xml parser

Description

fast-xml-parser is an open source, pure javascript xml parser. fast-xml-parser allows special characters in entity names, which are not escaped or sanitized. Since the entity name is used for creating a regex for searching and replacing entities in the XML body, an attacker can abuse it for denial of service (DoS) attacks. By crafting an entity name that results in an intentionally bad performing regex and utilizing it in the entity replacement step of the parser, this can cause the parser to stall for an indefinite amount of time. This problem has been resolved in v4.2.4. Users are advised to upgrade. Users unable to upgrade should avoid using DOCTYPE parsing by setting the `processEntities: false` option.

Affected products and versions

Product Affected versions Fixed in
fast-xml-parser 4.1 4.1.3 → < 4.2.4 4.2.4

References

Timeline

  1. Published
  2. Last modified

Other CVEs of fast-xml-parser

The 10 CVEs of fast-xml-parser →
CVE-2026-73569 fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks 8.7 High CVE-2026-41650 fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks 6.1 Medium CVE-2026-33349 fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks 5.9 Medium CVE-2026-33036 fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks 7.5 High
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