External risk intelligence

JetBrains Datalore Account Token Validation Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.1)

CVE-2026-123282

JetBrains Datalore is a data science platform commonly deployed as a web application or collaborative server environment. These services are frequently exposed to the internet or accessible via internal networks to facilitate remote team access and browser-based usage, making the authentication surface commonly reachable in typical deployments.

Jetbrains Datalore

before 2026.4

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability in JetBrains Datalore's account token handling could allow unauthorized access by bypassing expiration validation, potentially leading to new authenticated sessions. This issue affects the data science platform, which is often deployed in ways that make it accessible externally.

  • Unchecked token expirations enable unauthorized session creation.
  • Critical vulnerability impacts data science platform access.
  • Confirm relevance and potential exposure to data science users.

Attack Path

How an attacker could exploit the issue

An attacker could leverage a network connection to reach a vulnerable JetBrains Datalore instance. By exploiting a flaw in how account tokens are handled, an attacker could potentially establish a new authenticated session without proper validation, leading to unauthorized access and data compromise.

  • Network access is required.
  • Missing token expiration validation.
  • Unauthorized access and data compromise.

Live Threat

Current exploitation, exposure, and threat context

A missing expiration validation for account tokens could allow a new authenticated session to be created. This may affect system data, user data, service behavior, or sensitive information when supported by the advisory.

  • System tokens could be compromised.
  • An attacker could create a new authenticated session.
  • Unauthorized access to platform functionality.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in JetBrains Datalore, a data science platform, likely requires coordination between platform or infrastructure teams and application owners. The first practical step is to identify all Datalore instances, determine their accessibility and business criticality, and locate the responsible system owner. This will inform a risk-based remediation plan, potentially involving vendor coordination or controlled maintenance window scheduling.

  • Platform/App owners should manage remediation.
  • Verify Datalore instance reachability.
  • Plan coordinated updates or vendor engagement.

Supplementary metadata

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Frequently asked questions

What is JetBrains Datalore?

JetBrains Datalore is a collaborative data science platform designed for teams to write code, analyze data, and build models in a browser-based environment. It typically functions as a web-accessible server that manages computing resources and data files, allowing multiple users to work within shared projects and notebook sessions simultaneously.

What is the vulnerability in CVE-2026-123282?

This CVE involves a weakness classified as CWE-672, which refers to the expiration of a resource at a previous time. In plain terms, the software fails to properly check if an account token has expired. Because it does not discard old or invalid tokens, the system mistakenly accepts them as proof of identity, allowing someone to establish a new authenticated session.

How can an attacker trigger this vulnerability?

An attacker needs network access to reach a vulnerable Datalore instance. The bug is triggered when the system processes an account token that should have expired but is still accepted by the software. It is important to note that this flaw specifically relates to token validation logic; it does not depend on a specific user action or tricking a legitimate user into clicking a link.

Is my Datalore instance at risk?

According to Halo Surface Signal, Datalore is often deployed as a web application or collaborative server that is intentionally made accessible via the internet or internal networks to support remote team collaboration. If your instance is reachable over a network, it possesses the communication path required to potentially encounter this authentication issue.

What should I do to address this issue?

Start by identifying all instances of Datalore running in your environment and confirm their current version numbers. Coordinate with the teams responsible for these servers to determine their network reachability and business importance. This information will help you prioritize the necessary updates or vendor-provided patches once you verify the specific deployment status of your software.

References