CVE-2026-12228 parisneo CVE debrief

Who should care

Users of parisneo/lollms, particularly those hosting the application, should be aware of this vulnerability. An authenticated user can send a malicious prompt-share message to another user's inbox, leading to arbitrary JavaScript execution, authenticated actions as the victim, exposure of same-origin application data, and potential account takeover.

Technical summary

The vulnerability exists in the `POST /api/prompts/share` endpoint of parisneo/lollms. The endpoint stores attacker-controlled `prompt_content` into `DBDirectMessage.content` without server-side sanitization. The frontend sanitizer fails to comprehensively sanitize attacker-controlled HTML, allowing malicious payloads to execute in the victim's browser context. This enables any authenticated user to send a malicious prompt-share message to another user's inbox, leading to arbitrary JavaScript execution.

Defensive priority

High

Recommended defensive actions

• Apply the vendor's official patch or upgrade to a patched version.
• Implement additional input validation and sanitization for user-controlled input.
• Monitor for suspicious activity, such as unusual login attempts or changes to user accounts.
• Consider implementing a web application firewall (WAF) to detect and prevent XSS attacks.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The vulnerability was reported by [email protected] and is tracked as CVE-2026-12228. The NVD entry is currently Received. This stored cross-site scripting (XSS) vulnerability exists in the `POST /api/prompts/share` endpoint of parisneo/lollms. The endpoint stores attacker-controlled `prompt_content` into `DBDirectMessage.content` without server-side sanitization. When a victim opens the direct message (DM) thread, the message is rendered by the DM UI through `MessageContentRenderer`, which uses `v-html` to insert rendered HTML into the DOM. The frontend sanitizer, which is regex-based, fails to comprehensively sanitize attacker-controlled HTML, allowing malicious payloads to execute in the victim's browser context. Users of parisneo/lollms, particularly those hosting the application, should be aware of this vulnerability. An authenticated user can send a malicious prompt-share message to another user's inbox, leading to arbitrary JavaScript execution, authenticated actions as the victim, exposure of same-origin application data, and potential account takeover.

Official resources