CVE-2025-66481Public exploitNetwork attack vector

Code execution via incomplete Mermaid sanitization

Published Dec 9, 2025 · Updated Dec 9, 2025

Cross-site scripting in ThinkInAIXYZ DeepChat 0.5.1 and earlier allows remote attackers to execute code through crafted Mermaid content. MermaidArtifact.vue removes only quoted event-handler attributes with a regular expression, so unquoted attributes and HTML entities survive sanitization and execute after browser decoding. A victim must render the attacker-controlled Mermaid artifact; the injected JavaScript can call electron.ipcRenderer and start an arbitrary local process.

CVSS severity9.6
Critical
EPSS probability0.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in ThinkInAIXYZ DeepChat 0.5.1 and earlier allows remote attackers to execute code through crafted Mermaid content. MermaidArtifact.vue removes only quoted event-handler attributes with a regular expression, so unquoted attributes and HTML entities survive sanitization and execute after browser decoding. A victim must render the attacker-controlled Mermaid artifact; the injected JavaScript can call electron.ipcRenderer and start an arbitrary local process.

The record

CVE
CVE-2025-66481
Published
Dec 9, 2025
Updated
Dec 9, 2025
Vendor
ThinkInAIXYZ
Product
DeepChat
Classifications
CWE-80, CWE-79, CWE-94, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 9, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 9, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 0.5.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ThinkInAIXYZ · DeepChatversion=<= 0.5.1

Published CVSS scores

9.6GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-80Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-94Improper Control of Generation of Code ('Code Injection')
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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