CVE-2026-66298
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
A vulnerability in Livebook allows untrusted notebook JavaScript to trigger session-wide keyboard shortcuts, including forced evaluation of all cells and runtime restart. The issue stems from missing validation of keyboard events in the iframe and their forwarding to the main page.
Risk Assessment
Opening a notebook from an untrusted source can lead to execution of Elixir code without user consent, as well as loss of in-memory state due to runtime restart. Collaborators connected to the session may be affected by malicious outputs.
Recommendation
Immediately update Livebook to version 0.18.7 or 0.19.9 (depending on the branch). Until the update, avoid opening notebooks from untrusted sources.
Other vulnerabilities in Livebook
See all- CVE-2026-68746High
The 'Not Failing Securely' vulnerability in Livebook allows an unauthenticated network client to gain full access to a Livebook server that enforces identity through Livebook Teams. The issue arises from improper handling of an unresolvable deployment group identifier, which disables identity enforcement and grants full privileges.
- CVE-2026-66885Medium
A CSRF vulnerability in Livebook allows an attacker to authenticate a victim's browser session under the attacker's own Livebook Teams identity. The OAuth callback lacks state/nonce verification, enabling session identity substitution.
- CVE-2026-66881High
A Relative Path Traversal vulnerability in Livebook allows an attacker-authored notebook to write a file with attacker-controlled content to an arbitrary path. This occurs through importing file_entries metadata from a .livemd notebook without validating file names, enabling escape from the session's temporary directory.
- CVE-2026-66297High
An OS Command Injection vulnerability in Livebook allows injection of commands into generated Docker and Fly.io deployment setup commands. Deployment group environment variable values are interpolated into the commands without shell escaping, enabling arbitrary command execution via the shell.
Original NVD description (English source)
Origin Validation Error vulnerability in livebook-dev livebook allows untrusted notebook output JavaScript to trigger session-wide keyboard shortcuts, including forced evaluation of all cells and runtime restart. Livebook's JS-view feature renders notebook-defined JavaScript inside a sandboxed, cross-origin iframe specifically because that JavaScript is untrusted. The trusted iframe shell in iframe/priv/static/iframe/v5.html forwards every keydown event fired in its own window to the parent page without consulting Event.isTrusted, so an event synthesized by the untrusted script through window.dispatchEvent is forwarded exactly as a genuine keystroke would be. The parent-side relay in assets/js/hooks/js_view.js reconstructs and re-dispatches it on the live page with no further validation, and because assets/js/hooks/session.js registers the global shortcut handler on the document in the capture phase, that handler acts on the replicated event regardless of how it was produced. Sandboxed output JavaScript can therefore drive Livebook's session-wide keyboard shortcuts. Two of them reach LivebookWeb.SessionLive and execute immediately with no confirmation: the shortcut for queueing full evaluation runs every cell in the notebook, and the shortcut for reconnecting the runtime disconnects and reconnects it, discarding in-memory state. A third shortcut deletes the focused cell behind a confirmation dialog that the user can permanently dismiss, after which it too executes silently. Forced full evaluation is the significant consequence, because it causes the notebook's own Elixir code to run without the user choosing to evaluate anything. A user who merely opens a notebook obtained from a third party, or reached from published documentation, can have its code executed on their runtime. Livebook also mirrors cell outputs to every connected client, so a malicious output triggers in a collaborator's browser as soon as it renders. This issue affects livebook: from 0.5.0 before 0.18.7 and from 0.19.0 before 0.19.9.