seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In versions 1.4.0 and below, improper input handling in the JSON deserialization component can lead to arbitrary JavaScript code execution. Exploitation is possible via overriding constant value and error deserialization, allowing indirect access to unsafe JS evaluation. At minimum, attackers need the ability to perform 4 separate requests on the same function, and partial knowledge of how the serialized data is used during later runtime processing. This vulnerability affects the fromJSON and fromCrossJSON functions in a client-to-server transmission scenario. This issue has been fixed in version 1.4.0.

Affected: npm: seroval

Improper input handling in the JSON deserialization component can lead to arbitrary JavaScript code execution.

The vulnerability can be exploited via overriding constant value and error deserialization, which allows indirect access to unsafe JS evaluation. This requires at least the ability to perform 4 separate requests on the same function and partial knowledge of how the serialized data is used during later runtime processing.

This vulnerability affects the `fromJSON` and `fromCrossJSON` functions in a client-to-server transmission scenario.

No known workarounds or mitigations are known, so please upgrade to the patched version.

opencode-1.18.26-1.1 on GA media