Raw vector
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2025-66562 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Aiql Tuui. Its CVSS base score is 8.9 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 41th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
This vulnerability is AI-related — categorised as AI Agent Protocols and Integrations; in the Protocol-Specific Risks risk domain.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2025-66562 is a critical remote code execution (RCE) vulnerability affecting TUUI, a desktop MCP client designed as a tool for unitary utility integration, in versions prior to 1.3.4. The flaw stems from an unsafe cross-site scripting (XSS) issue in the Markdown rendering component (CWE-79), which permits the execution of arbitrary JavaScript within ECharts code blocks (CWE-94). This vulnerability has a CVSS v3.1 base score of 9.6 (AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H), highlighting its high severity due to network accessibility, low attack complexity, and comprehensive impact on confidentiality, integrity, and availability.
A remote attacker can exploit this vulnerability by crafting a malicious Markdown message containing JavaScript in an ECharts code block. When a victim views the message in TUUI, the JavaScript executes in the application's context and leverages an exposed IPC interface capable of spawning processes, enabling the attacker to run arbitrary system commands on the victim's machine. No authentication or privileges are required, though user interaction is necessary to view the malicious content.
The vulnerability is addressed in TUUI version 1.3.4, as detailed in the project's GitHub security advisory (GHSA-qjhq-rgmr-6c3g), release notes, and the fixing commit. Security practitioners should advise users to update to v1.3.4 or later to mitigate the risk.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-201459
Vulnerability Data
TUUI is a desktop MCP client designed as a tool unitary utility integration. Prior to 1.3.4, a critical Remote Code Execution (RCE) vulnerability exists in Tuui due to an unsafe Cross-Site Scripting (XSS) flaw in the Markdown rendering component. Tuui…
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allows the execution of arbitrary JavaScript within ECharts code blocks. Combined with an exposed IPC interface that allows spawning processes, an attacker can execute arbitrary system commands on the victim's machine simply by having them view a malicious Markdown message. This vulnerability is fixed in 1.3.4.
- CWE(s)
AI Security AnalysisAI
- AI Category
- AI Agent Protocols and Integrations
- Risk Domain
- Protocol-Specific Risks
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: mcp
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.1.2V1.3.2V1.3.1
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover missing or incorrect input neutralization through targeted web-application tests.
Input validation directly enforces neutralization of untrusted data before it reaches web output generation.
Output filtering can catch or sanitize unneutralized script content before it is served to users.
Least privilege limits the damage an injected code fragment can perform once executed.
Requiring documented secure development standards and tools enforces use of safe code-generation APIs and escaping.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).
Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).
PR.DS-10 protects runtime data confidentiality/integrity but has no bearing on neutralizing externally influenced input during code generation, so neither direction shows any preventive effect.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.
Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.
Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.
Requiring language-specific secure-coding standards and automated scanning during the SDLC catches missing output encoding or improper neutralization of untrusted data before the software reaches production.
Secure-coding standards, SAST scans and removal of insecure code samples together eliminate the failure to neutralize script content that produces cross-site scripting flaws.