Description

CERT Polska has received a report about vulnerabilities in Logseq software and participated in coordination of their disclosure.

The vulnerability CVE-2026-9279: Logseq exposes an IPC handler that allows the renderer process to execute shell commands. While an allowlist restricts the command name (e.g. git, pandoc, grep), the argument string is concatenated with the command and passed to child_process.spawn with the shell: true option, allowing shell metacharacters in the arguments to bypass the allowlist. An attacker with JavaScript execution in the renderer (e.g. via XSS or a malicious plugin) can execute arbitrary shell commands with the privileges of the Logseq process, leading to remote code execution on the host.

The vulnerability CVE-2026-47899: The Electron preload script in Logseq exposes an API method that allows the renderer process to invoke IPC handlers without proper path validation. An attacker with JavaScript execution in the renderer (e.g. via XSS or a malicious plugin), can read, write, or delete arbitrary files on the user's system.

The vulnerability CVE-2026-47900: Logseq is vulnerable to a stored cross-site scripting (XSS). A malicious plugin can include a JavaScript payload in the name field of its package.json file, which is rendered using innerHTML without proper sanitization, allowing the execution of arbitrary code in the privileged host context.

The vulnerability CVE-2026-47901: 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 the vendor.

Credits

We thank Bartłomiej Dmitruk (striga.ai) for the responsible vulnerability report.