HighCVE-2026-68746

Livebook: Failing Open (CVE-2026-68746)

Published 05.08.2026Last modified 24.10.2026Sources: CVE.org, OSV

What is affected, what to do

Update Livebook to version 0.19.9, Livebook to version 0.19.9-cuda12.

Affected: Livebook lt 0.19.7..0.19.9
Livebook lt 0.19.7-cuda12..0.19.9-cuda12
Fixed in: Livebook 0.19.9
Livebook 0.19.9-cuda12

Not sure whether and how you are affected? Ask a question about this vulnerability

Metrics

8.8

Priority

XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

Source: NVD, CVSS v3

8.8

CVSS v3

Severity High on the scale from 0 to 10.

Source: CVE.org, OSV

0.8 %

EPSS score

Low — model estimates < 1% exploitation likelihood.

Source: FIRST EPSS, percentile 56.7

Show all metrics

Severity: High
Priority (0–325) The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first? Read in glossary: 91.66 Methodology
Exploit maturity An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack. Read in glossary: no public PoC known
XIEM Effective CVSS XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command. Read in glossary: 8.8 Methodology
CVSS v3 CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions. Read in glossary: 8.8
CVSS v4 CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions. Read in glossary: 7.7
EPSS score The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“. Read in glossary: 0.8 %; Low — model estimates < 1% exploitation likelihood.
EPSS percentile The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking. Read in glossary: 56.7; High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
KEV status The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching. Read in glossary: —
Published: 05.08.2026
CISA assessment (SSVC): Exploitation: none known · not automatable · Technical impact: total; Source: CISA Vulnrichment, as of 6 August 2026
CWE CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect. Read in glossary: CWE-636

Detection rules

No NEOSEC detection rule is available for this vulnerability yet.

Classification under NIS2 and CRA

Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

NIS2 NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management. Read in glossary: High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates. Read in glossary: From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001 ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security. Read in glossary: Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

Description

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.

Source: NVD (NIST), cvelistv5, OSV (Open Source Vulnerabilities)

Affected products

The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

Affected products
		Affected versions	Fixed in
livebook-dev	livebook	`0.19.7-cuda12 – < 0.19.9-cuda12` `0.19.7 – < 0.19.9`	`0.19.9-cuda12` `0.19.9`
livebook	livebook	`0.19.7 – < 0.19.9`	`0.19.9`
hex	livebook	`0.19.7` `0.19.8`	— —

Vendors and products

Weakness classes (CWE)

CWE-636Not Failing Securely ('Failing Open')
Class
When the product encounters an error condition or failure, its design requires it to fall back to a state that is less secure than other options that are available, such as selecting the weakest encryption algorithm or using the most permissive access control restrictions.
Entry at MITRE CWE-636

References & sources

github.comlivebook-dev/livebook/security/advisories/GHSA-74j5-6grg-g6wjadvisory, Vendor advisory, related, Vendor advisory
cna.erlef.orgcves/CVE-2026-68746.htmlweb, related, Vendor advisory
github.comlivebook-dev/livebook/commit/d374e90647edbb00286bfee9182c0161d2…fix, Patch, Patch
github.comlivebook-dev/livebook/commit/d6d0dfa746b172540442852f74de4a9dea…fix, Patch, Patch
github.comlivebook-dev/livebook/commit/2d3a2c710c880abd24a2bc888d3cf5239d…fix, Patch, Patch
hex.pmpackages/livebookpackage
OSV (Open Source Vulnerabilities)vulnerability/EEF-CVE-2026-68746related, Third-party advisory

Changes to this CVE

Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

10.08.2026Initial analysis by NVDNVD

Newly listed as affected:

Livebook (0.19.7 – before 0.19.9)

CVSS V3.1: AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

New references:

and 2 more references

Show 8 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
CVSS	added	—	AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Product configuration	added	—	OR cpe:2.3:a:livebook:livebook::::::::* versions from (including) 0.19.7 up to (excluding) 0.19.9
Reference type	added	—	EEF: https://cna.erlef.org/cves/CVE-2026-68746.html Types: Vendor Advisory
Reference type	added	—	EEF: https://github.com/livebook-dev/livebook/commit/2d3a2c710c880abd24a2bc888d3cf5239d98cf72 Types: Patch
Reference type	added	—	EEF: https://github.com/livebook-dev/livebook/commit/d374e90647edbb00286bfee9182c0161d29a8e07 Types: Patch
Reference type	added	—	EEF: https://github.com/livebook-dev/livebook/commit/d6d0dfa746b172540442852f74de4a9deacc433b Types: Patch
Reference type	added	—	EEF: https://github.com/livebook-dev/livebook/security/advisories/GHSA-74j5-6grg-g6wj Types: Vendor Advisory
Reference type	added	—	EEF: https://osv.dev/vulnerability/EEF-CVE-2026-68746 Types: Third Party Advisory

Source identifier: nvd@nist.gov

06.08.2026Record modifiedCISA ADP

CISA assessment (SSVC): exploitation: none known, automatable: no

Show the original change

Individual changes of this event as published by NVD
Type	Action	Before	After
SSVC assessment	added	—	{"id":"CVE-2026-68746","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-08-06T14:45:09.939122Z"}

Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

05.08.2026ReceivedEEF

CVSS V4.0: AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Weakness type: CWE-636

Description added or changed

New references:

and 2 more references

Show 10 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Affected versions (publisher)	added	—	livebook, livebook, livebook
Description	added	—	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.
CVSS	added	—	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
Weakness type (CWE)	added	—	CWE-636
Reference	added	—	https://cna.erlef.org/cves/CVE-2026-68746.html
Reference	added	—	https://github.com/livebook-dev/livebook/commit/2d3a2c710c880abd24a2bc888d3cf5239d98cf72
Reference	added	—	https://github.com/livebook-dev/livebook/commit/d374e90647edbb00286bfee9182c0161d29a8e07
Reference	added	—	https://github.com/livebook-dev/livebook/commit/d6d0dfa746b172540442852f74de4a9deacc433b
Reference	added	—	https://github.com/livebook-dev/livebook/security/advisories/GHSA-74j5-6grg-g6wj
Reference	added	—	https://osv.dev/vulnerability/EEF-CVE-2026-68746

Source identifier: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

2 NVD translations into other languages are hidden.

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