CVE-2026-43899: critical vulnerability in ThinkInAIXYZ deepchat
DeepChat: Incomplete Fix for CVE-2025-55733 leads to Remote Code Execution via Markdown Links bypassing `isValidExternalUrl`
Published · Updated
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28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.6epss 0.4%
DeepChat is an open-source artificial intelligence agent platform that unifies models, tools, and agents. Prior to v1.0.4-beta.1, An incomplete mitigation for CVE-2025-55733 leaves DeepChat vulnerable to an arbitrary protocol execution bypass (RCE). While the patch correctly restricted api.openExternal() inside the renderer's preload/index.ts script, it structurally neglected to sanitize native Electron pop-up window handlers. An attacker or a compromised AI endpoint returning a Markdown link can trigger a target="_blank" native window interception in tabPresenter.ts, which forwards the malicious URL directly to shell.openExternal(url) and completely bypasses the isValidExternalUrl security boundary. This vulnerability is fixed in v1.0.4-beta.1.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Affected products
ThinkInAIXYZ · deepchatRelated CVEs — ThinkInAIXYZ deepchat
In the same product, most dangerous first.
CVE-2025-55733CRITICALDeepChat One-click Remote Code Execution through Custom URL HandlingEPSS 0.7%CVE-2025-67744CRITICALMermaid XSS vulnerability leads to Remote Code ExecutionEPSS 0.6%CVE-2025-66222CRITICALDeepChat Cross-Site Scripting(XSS) escalate to Remote Code Execution(RCE)EPSS 0.6%CVE-2025-58768CRITICALDeepChat's Mermaid rendering has XSS leading to RCEEPSS 0.6%CVE-2025-66481CRITICALDeepChat's Incomplete XSS Fix Allows RCE through Mermaid ContentEPSS 0.6%CVE-2026-43900CRITICALDeepChat: Persistent DOM XSS via HTML Entity Encoding in `<antArtifact>` SVG Rendering (Bypass of `svgSanitizer.ts`)EPSS 0.4%