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.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.