Livebook-dev Livebook up to 0.19.7/0.19.8 team_client.ex Livebook.Hubs.TeamClient.handle_call improper authorization

Summaryinfo

A vulnerability was found in Livebook-dev Livebook up to 0.19.7/0.19.8. It has been rated as critical. The impacted element is the function Livebook.Hubs.TeamClient.handle_call of the file lib/livebook/hubs/team_client.ex. The manipulation leads to improper authorization. This vulnerability is listed as CVE-2026-68746. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in Livebook-dev Livebook up to 0.19.7/0.19.8 and classified as critical. This issue affects the function Livebook.Hubs.TeamClient.handle_call of the file lib/livebook/hubs/team_client.ex. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-68746 since 07/31/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

Upgrading to version 0.19.9 eliminates this vulnerability.

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Productinfo

Vendor

• Livebook-dev

Name

• Livebook

Version

• 0.19.0
• 0.19.1
• 0.19.2
• 0.19.3
• 0.19.4
• 0.19.5
• 0.19.6
• 0.19.7
• 0.19.8

Website

• Product: https://github.com/livebook-dev/livebook/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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