The vulnerability exists in the parisneo/lollms application's POST /api/prompts/share endpoint, where the prompt_content field is stored directly into DBDirectMessage.content without proper server-side sanitization. The frontend uses a regex-based sanitizer that is insufficient, and the message content is rendered using v-html, which inserts HTML directly into the DOM. This allows an authenticated attacker to send malicious prompt-share messages that execute arbitrary JavaScript in the context of the victim's browser when they view the direct message thread. The vulnerability enables actions such as executing authenticated requests as the victim, stealing same-origin data, and potentially taking over the victim's account. The CVSS 3.0 score is 8.7 (High), reflecting network attack vector, low attack complexity, required privileges, user interaction, and high impact on confidentiality and integrity.

An authenticated attacker can exploit this vulnerability to execute arbitrary JavaScript in the context of a victim user’s browser. This can lead to unauthorized actions performed with the victim's privileges, exposure of sensitive application data, and potential account takeover. The vulnerability compromises confidentiality and integrity but does not impact availability.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should exercise caution when interacting with prompt-share messages from untrusted sources. The vendor has not provided an official fix or temporary mitigation at this time.