An unsafe HTML rendering path in 5ire allows untrusted HTML—including event handler attributes—to be executed in the renderer process. By injecting a payload such as `<img onerror=...>`, an attacker can run arbitrary JavaScript. This JavaScript can call exposed bridge APIs like `window.bridge.mcpServersManager.createServer`, enabling the attacker to create new MCP servers and ultimately execute remote commands on the host system.

The vulnerability affects the 5ire application developed by nanbingxyz. All releases prior to version 0.15.3 are impacted. Version 0.15.3 and later contain the fix.

The vulnerability has a CVSS score of 9.7, indicating critical severity. The EPSS score is less than 1%, suggesting a low probability of exploitation as of this analysis, and the vulnerability is not listed in CISA’s KEV catalog. Based on the description, the attack requires delivery of malicious HTML content to the renderer, which could be achieved by an attacker who can influence the content viewed by the application. The bridge API exposure further elevates the impact to full remote code execution on the host.