# CVE-2025-66222: DeepChat Cross-Site Scripting(XSS) escalate to Remote Code Execution(RCE)

> Stored XSS in DeepChat's Mermaid renderer allows attackers to execute arbitrary code via Electron IPC bridge escalation.

- **Severity:** Critical 9.7 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 3 Dec 2025
- **Updated:** 3 Dec 2025
- **Also known as:** GHSA-v8v5-c872-mf8r

## What is CVE-2025-66222?

CVE-2025-66222 is a critical cross-site scripting vulnerability in ThinkInAIXYZ deepchat, published on 3 Dec 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

DeepChat is a smart assistant uses artificial intelligence. In 0.5.0 and earlier, there is a Stored Cross-Site Scripting (XSS) vulnerability in the Mermaid diagram renderer allows an attacker to execute arbitrary JavaScript within the application context. By leveraging the exposed Electron IPC bridge, this XSS can be escalated to Remote Code Execution (RCE) by registering and starting a malicious MCP (Model Context Protocol) server.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2025-66222?

It affects 1 product.


Products: Thinkinai Deepchat.

## How do I fix CVE-2025-66222?

No fix has been published for CVE-2025-66222 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-66222 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-66222 exists.

## Other vulnerabilities in ThinkInAIXYZ deepchat

- [CVE-2025-67744](https://insights.sbomify.com/CVE-2025-67744/): Mermaid XSS vulnerability leads to Remote Code Execution (critical 9.7)
- [CVE-2025-66481](https://insights.sbomify.com/CVE-2025-66481/): DeepChat's Incomplete XSS Fix Allows RCE through Mermaid Content (critical 9.7)
- [CVE-2025-58768](https://insights.sbomify.com/CVE-2025-58768/): DeepChat's Mermaid rendering has XSS leading to RCE (critical 9.7)
- [CVE-2025-55733](https://insights.sbomify.com/CVE-2025-55733/): DeepChat One-click Remote Code Execution through Custom URL Handling (critical 9.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-66222 and fix it if it is affected.

What it is: CVE-2025-66222 is a critical cross-site scripting vulnerability in ThinkInAIXYZ deepchat, published on 3 Dec 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-66222 exists.

Affected product: ThinkInAIXYZ deepchat. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-66222/ (Markdown: https://insights.sbomify.com/CVE-2025-66222/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-66222
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-66222
- OSV: https://osv.dev/vulnerability/CVE-2025-66222

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-66222/
Summaries are generated and may contain mistakes; the official description above is the record.