Spring Web Flow's JavaScript RemotingHandler component fails to properly neutralize input during web page generation, specifically by rendering error response bodies as HTML regardless of the content type. This improper handling can lead to cross-site scripting (CWE-79) when error responses include attacker-controlled input reflected in the response. The affected versions are exactly 4.0.0, 3.0.0, and 2.5.0. No official patch or remediation level has been provided in the available data.

Successful exploitation could allow an attacker to execute arbitrary scripts in the context of the user's browser, potentially leading to session hijacking or other malicious actions. The vulnerability does not impact confidentiality or availability but impacts integrity through script injection. The CVSS vector indicates that exploitation requires network access, high attack complexity, low privileges, and user interaction.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch is currently documented. Until a patch is available, users should consider applying custom input validation or sanitization on error responses and avoid reflecting untrusted input in error messages. Monitoring vendor channels for updates is recommended.