CVE-2026-68746
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk30th percentile - higher than 30% of all known CVEs
Summary
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.
Risk Assessment
An attacker can read notebooks and configured secrets, execute code on the server's runtime, and disrupt its operation, posing a serious threat to the confidentiality and integrity of organizational data.
Recommendation
Immediately upgrade Livebook to version 0.19.9 or later, which includes the fix. Also restrict network access to the Livebook server to trusted clients only.
Other vulnerabilities in Livebook
See all- 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-2026-66298High
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.
- 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)
Not Failing Securely ('Failing Open') vulnerability in livebook-dev livebook allows an unauthenticated network client to obtain full access to a Livebook server that enforces identity through Livebook Teams. A Livebook Agent or App Server connected to Livebook Teams caches the identifier of the deployment group it belongs to, and resolves that identifier against a locally cached list of deployment groups on every request in order to decide whether Teams identity enforcement is active. Livebook.Hubs.TeamClient.handle_call/3 in lib/livebook/hubs/team_client.ex does not distinguish a deployment group that could not be resolved from one that was resolved with identity enforcement switched off: the clause matches only the case where a group was found with enforcement enabled, and falls through to a catch-all that reports enforcement as switched off for everything else. The two neighbouring functions that decide user and application access resolve the same identifier and treat the same unresolved result as a denial. When the identity status is reported as switched off, Livebook.ZTA.LivebookTeams.authenticate/3 in lib/livebook/zta/livebook_teams.ex returns empty identity metadata and allows the request to continue instead of halting it. LivebookWeb.UserPlug.build_current_user/3 merges that empty metadata into a newly built user, whose access type defaults to full access, and LivebookWeb.AuthPlug.authorized?/1 grants access to any user holding full access. The cached identifier becomes unresolvable when the deployment group it refers to is deleted while the agent is not connected to receive the change, most concretely when a deployment group is deleted during the window in which an agent is disconnected or reconnecting. The client removes the group from its cached list without clearing the identifier that refers to it. Any client able to reach the affected server over the network is then granted the same access as a fully privileged member of the organisation, including the ability to read notebooks and configured secrets, execute code on the server's runtime, and disrupt its operation. This issue affects livebook: from 0.19.7 before 0.19.9.