CVE-2026-43900: DeepChat: Persistent DOM XSS via HTML Entity Encoding in `<antArtifact>` SVG Rendering (Bypass of `svgSanitizer.ts`)
DeepChat is an open-source artificial intelligence agent platform that unifies models, tools, and agents. Prior to v1.0.4-beta.1, a Cross-Site Scripting (XSS) vulnerability exists due to a discrepancy between the backend validation layer and the frontend browser rendering engine. The SVGSanitizer (src/main/lib/svgSanitizer.ts) restricts script execution by scrubbing javascript: protocols using plain-text regular expressions. However, it fails to account for HTML entity decoding prior to Vue's v-html DOM insertion inside the SvgArtifact.vue component. By feeding an SVG artifact with obfuscated entities (e.g., javascript:alert(1)), an attacker can completely bypass the sanitizer, culminating in arbitrary JavaScript execution when a victim interacts with the rendered SVG Element. This vulnerability is fixed in v1.0.4-beta.1.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-43900?
CVE-2026-43900 is considered a high-severity vulnerability due to the potential for persistent DOM-based Cross-Site Scripting (XSS) attacks.
How do I fix CVE-2026-43900?
To fix CVE-2026-43900, users should update their DeepChat software to version 1.0.4-beta.1 or later.
What impact does CVE-2026-43900 have on DeepChat users?
CVE-2026-43900 allows attackers to execute malicious scripts in the context of users' browsers, potentially compromising user data.
Is CVE-2026-43900 present in versions before 1.0.4-beta.1 of DeepChat?
Yes, CVE-2026-43900 exists in all DeepChat versions prior to 1.0.4-beta.1.
Who is affected by CVE-2026-43900?
Any user or organization utilizing DeepChat versions before 1.0.4-beta.1 is affected by CVE-2026-43900.