CVE-2026-69116 in FlyEnv
Summary
by MITRE • 08/10/2026
FlyEnv before 4.18.0 fails to sanitize HTML from markdown rendering and AI chat content passed to Vue v-html directives. Attackers can inject malicious scripts through markdown sources or chat messages that execute in the Electron renderer process with access to Node.js APIs and the filesystem.
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Analysis
by VulDB Data Team • 08/10/2026
The vulnerability in FlyEnv versions prior to 4.18.0 represents a critical server-side request forgery and cross-site scripting risk stemming from improper HTML sanitization within the application's markdown rendering and AI chat functionality. This flaw allows attackers to inject malicious scripts through crafted markdown content or chat messages that are subsequently processed by Vue.js v-html directives without adequate sanitization measures. The vulnerability directly exploits the trust placed in user-generated content within the Electron-based application environment where the renderer process maintains access to Node.js APIs and filesystem operations, creating a severe attack surface for privilege escalation.
The technical implementation of this vulnerability stems from the application's failure to properly sanitize HTML output when rendering markdown content or AI-generated chat responses. When the Vue v-html directive processes untrusted input, it directly inserts the HTML into the DOM without validating or filtering potentially dangerous elements such as script tags, event handlers, or malicious iframe content. This sanitization failure creates an environment where attackers can inject malicious payloads that execute within the Electron renderer process, which operates with elevated privileges including access to Node.js native modules and file system operations.
The operational impact of this vulnerability extends beyond traditional web application security concerns into the realm of desktop application exploitation where the consequences are significantly more severe. Attackers leveraging this vulnerability can potentially access sensitive files, execute arbitrary code, establish persistence mechanisms, or exfiltrate data from the victim's system. The Electron framework context amplifies the risk because the renderer process typically has access to Node.js APIs that provide direct filesystem access, process management capabilities, and network operations that are normally restricted in web applications. This creates opportunities for attackers to escalate privileges, perform lateral movement within the user's environment, or establish command and control channels.
Security professionals should address this vulnerability through comprehensive input validation and output sanitization measures that align with established security frameworks such as CWE-79 for cross-site scripting and CWE-1004 for insecure deserialization. The remediation approach must include implementing robust HTML sanitization libraries such as DOMPurify or similar solutions that can properly filter malicious content before insertion into the DOM through Vue.js directives. Additionally, organizations should consider implementing Content Security Policy headers, disabling inline script execution, and employing strict input validation for all user-provided content. The fix should also address the underlying architecture by ensuring that markdown rendering and chat functionality do not directly pass untrusted content to v-html directives without proper sanitization.
From an ATT&CK framework perspective, this vulnerability maps to several techniques including T1059.007 for command and script interpreter usage, T1068 for exploit for privilege escalation, and T1566 for malicious input injection. The attack chain typically begins with initial access through content injection followed by privilege escalation within the Electron environment. Organizations should implement monitoring for unusual file system activity, process execution patterns, and network connections that may indicate exploitation attempts. The remediation process should also include regular security assessments of third-party libraries and frameworks to ensure proper sanitization practices are maintained throughout the application lifecycle.