CVE-2026-33349
MEDIUM
5,9
Source: [email protected]
Attack Vector: network
Attack Complexity: high
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: none
Integrity: none
Availability: high
Description
AI Translation Available
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.
1284
Improper Validation of Specified Quantity in Input
IncompleteCommon Consequences
Security Scopes Affected:
Other
Integrity
Availability
Potential Impacts:
Varies By Context
Dos: Resource Consumption (Cpu)
Modify Memory
Read Memory
Applicable Platforms
All platforms may be affected
https://github.com/NaturalIntelligence/fast-xml-parser/commit/239b64aa1fc5c5455…
https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA…