CVE-2025-62410
October 15, 2025
In versions before 20.0.2, it was found that --disallow-code-generation-from-strings is not sufficient for isolating untrusted JavaScript in happy-dom. The untrusted script and the rest of the application still run in the same Isolate/process, so attackers can deploy prototype pollution payloads to hijack important references like "process" in the example below, or to hijack control flow via flipping checks of undefined property. This vulnerability is due to an incomplete fix for CVE-2025-61927. The vulnerability is fixed in 20.0.2.
Affected Packages
happy-dom (NPM):
Affected version(s) >=0.0.1 <20.0.2Fix Suggestion:
Update to version 20.0.2happy-dom (NPM):
Affected version(s) >=19.0.0 <20.0.2Fix Suggestion:
Update to version 20.0.2Related Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
9.4
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
PASSIVE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
HIGH
Subsequent System Integrity
HIGH
Subsequent System Availability
HIGH
CVSS v3
Base Score:
9
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
EPSS
Base Score:
0.10
