fast-xml-parser: Entity Expansion Limits Bypassed When Set to Zero Due to JavaScript Falsy Evaluation
Résumé
fast-xml-parser: Entity Expansion Limits Bypassed When Set to Zero Due to JavaScript Falsy Evaluation
Description d'origine
La description telle que publiée par la source (souvent en anglais).
fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. From version 4.0.0-beta.3 to before version 5.5.7, the DocTypeReader in fast-xml-parser uses JavaScript truthy checks to evaluate maxEntityCount and maxEntitySize configuration limits. When a developer explicitly sets either limit to 0 — intending to disallow all entities or restrict entity size to zero bytes — the falsy nature of 0 in JavaScript causes the guard conditions to short-circuit, completely bypassing the limits. An attacker who can supply XML input to such an application can trigger unbounded entity expansion, leading to memory exhaustion and denial of service. This issue has been patched in version 5.5.7.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
État des correctifs par distribution
Paquets corrigés publiés par chaque distribution pour cette CVE
- Debian DEBIAN-CVE-2026-33349 node-webfont
- Ubuntu UBUNTU-CVE-2026-33349 node-webfont
Références
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- patch github.com