Livebook Teams identity check fails open when the deployment group is unresolvable, allowing unauthenticated access

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-68746
StatePUBLISHED
AssignerEEF
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-05 20:17:14 UTC
Updated2026-08-05 20:17:14 UTC
DescriptionNot 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.

Risk And Classification

Primary CVSS: v4.0 7.7 HIGH from 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Problem Types: CWE-636 | CWE-636 CWE-636 Not Failing Securely ('Failing Open')

VersionSourceTypeScoreSeverityVector
4.06b3ad84c-e1a6-4bf7-a703-f496b71e49dbSecondary7.7HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS7.7HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
Low
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Livebook-dev Livebook affected 0.19.7 0.19.9 semver Not specified
CNA Livebook-dev Livebook affected 0.19.7 0.19.9 other Not specified
CNA Livebook-dev Livebook affected 0.19.7-cuda12 0.19.9-cuda12 other Not specified
CNA Livebook-dev Livebook affected fc2c87c6b0276705281842acbe17142d1ac4d555 * git Not specified

References

ReferenceSourceLinkTags
github.com/livebook-dev/livebook/commit/2d3a2c710c880abd24a2bc888d3cf523... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
github.com/livebook-dev/livebook/commit/d374e90647edbb00286bfee9182c0161... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
github.com/livebook-dev/livebook/commit/d6d0dfa746b172540442852f74de4a9d... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
cna.erlef.org/cves/CVE-2026-68746.html 6b3ad84c-e1a6-4bf7-a703-f496b71e49db cna.erlef.org
osv.dev/vulnerability/EEF-CVE-2026-68746 6b3ad84c-e1a6-4bf7-a703-f496b71e49db osv.dev
github.com/livebook-dev/livebook/security/advisories/GHSA-74j5-6grg-g6wj 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Nguyễn Công Tú (en)

CNA: Jonatan Kłosko (en)

CNA: José Valim (en)

CNA: Hugo Baraúna (en)

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