The vulnerability CVE-2026-4964 affects letta-ai letta 0.16.4 in the File URL Handler component. Specifically, the function _convert_message_create_to_message in letta/helpers/message_helper.py improperly processes the ImageContent argument, enabling server-side request forgery. This allows remote attackers to induce the server to make unintended requests. The vulnerability is publicly disclosed with no known exploits in the wild and no vendor response or patch available at this time.

Successful exploitation of this SSRF vulnerability could allow an attacker to cause the affected server to send crafted requests to internal or external resources, potentially leading to information disclosure or interaction with internal systems. However, the CVSS score and vector indicate limited impact due to low complexity and privileges required, and no user interaction needed. No known active exploitation has been reported.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since the vendor has not responded or provided a fix, users should monitor official channels for updates. Until a patch is available, consider implementing network-level controls to restrict outbound requests from the affected component and validate or sanitize inputs related to ImageContent to mitigate potential SSRF exploitation.