Logseq is vulnerable to a sandbox escape flaw where plugins running in sandboxed iframes can inject arbitrary HTML attributes, such as event handlers, into their container element in the host DOM. Due to a disabled Content Security Policy (CSP), this allows a malicious plugin to execute arbitrary JavaScript in the privileged host context, potentially gaining unauthorized access to filesystem APIs.
While only version v0.10.15 was tested and confirmed as vulnerable, status of other versions is unknown since this issue was not addressed by a patch.