Description
The XML parser can be forced to do an unlimited amount of entity expansion. With a very small XML input, it’s possible to make the parser spend seconds or even minutes processing a single request, effectively freezing the application.
Recommendation
Update the fast-xml-parser package to the latest compatible version. Followings are version details:
Affected version(s): **>= 5.0.0, < 5.3.6 >= 4.1.3, < 4.5.4** Patched version(s): **5.3.6 4.5.4**
References
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Start a free scanRelated Issues
- fast-xml-parser: Repeated DOCTYPE declarations reset entity expansion limits - CVE-2026-73569
- fast-xml-parser affected by numeric entity expansion bypassing all entity expansion limits (incomplete fix for CVE-2026- - CVE-2026-33036
- fast-xml-parser has an entity encoding bypass via regex injection in DOCTYPE entity names - CVE-2026-25896
- Entity Expansion Limits Bypassed When Set to Zero Due to JavaScript Falsy Evaluation in fast-xml-parser - CVE-2026-33349
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See something that needs correcting? Let us knowUpdated February 27, 2026