fast-xml-parser@5.5.2 vulnerabilities

Validate XML, Parse XML, Build XML without C/C++ based libraries

  • latest version

    5.5.8

  • latest non vulnerable version

  • first published

    9 years ago

  • latest version published

    3 days ago

  • licenses detected

  • Direct Vulnerabilities

    Known vulnerabilities in the fast-xml-parser package. This does not include vulnerabilities belonging to this package’s dependencies.

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    VulnerabilityVulnerable Version
    • H
    Improper Validation of Specified Quantity in Input

    fast-xml-parser is a Validate XML, Parse XML, Build XML without C/C++ based libraries

    Affected versions of this package are vulnerable to Improper Validation of Specified Quantity in Input in the DocTypeReader component when the maxEntityCount or maxEntitySize configuration options are explicitly set to 0. Due to JavaScript's falsy evaluation, the intended limits are bypassed. An attacker can cause unbounded entity expansion and exhaust server memory by supplying crafted XML input containing numerous large entities.

    Note:

    This is only exploitable if the application is configured with processEntities enabled and either maxEntityCount or maxEntitySize set to 0.

    How to fix Improper Validation of Specified Quantity in Input?

    Upgrade fast-xml-parser to version 5.5.7 or higher.

    >=4.0.0-beta.3 <5.5.7
    • H
    XML Entity Expansion

    fast-xml-parser is a Validate XML, Parse XML, Build XML without C/C++ based libraries

    Affected versions of this package are vulnerable to XML Entity Expansion in the replaceEntitiesValue() function, which doesn't protect unlimited expansion of numeric entities the way it does DOCTYPE data (as described and fixed for CVE-2026-26278). An attacker can exhaust system memory and CPU resources by submitting XML input containing a large number of numeric character references - &#NNN; and &#xHH;.

    Note: This is a bypass for the fix to the DOCTYPE expansion vulnerability in 5.3.6.

    How to fix XML Entity Expansion?

    Upgrade fast-xml-parser to version 5.5.6 or higher.

    >=4.0.0-beta.0 <5.5.6