The flaw lies in the processMessages function of message-processor.ts, where dynamically determined object attributes are set without proper validation. An attacker who can reach the that force the application to assign object properties that are normally restricted. This vulnerability is classified as CWE-913 and CWE-915, indicating improper control of resource allocation and improper validation of object names. While the CVE description does not confirm remote code execution, the uncontrolled manipulation of object attributes could allow an attacker to alter application state, overwrite critical data, or potentially elevate privileges within the application context.

Deployments of the a2ui-project a2ui package version 0.10.6 or earlier are affected. The vulnerable function resides in renderers/web_core/src/v0_9/processing/message-processor.ts of the Message Parsing component. Any environment that exposes this processing endpoint to untrusted input, such as via a WebSocket or REST API, could be at risk. Versions newer than 0.10.6 are not listed as vulnerable.

The CVSS base score of 5.3 places the vulnerability in the medium risk range than 1 % suggests a very low but non‑zero likelihood of exploitation. The issue is not listed in the CISA KEV catalog. Exploitation requires remote access to the message parsing endpoint and the ability to send crafted messages; no public exploit code has been reported. Therefore, organizations should evaluate whether the message endpoint is exposed to untrusted messages to reduce the attack surface.