---
id: "CVE-2026-123835"
page: "https://infrastack.ai/live/CVE-2026-123835"
kind: "vulnerability"
aliases: ["CVE-2026-123835"]
title: "JetBrains Datalore: init script upload race lets one user run code in another's computation"
severity: "medium"
cvss: 5.9
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["datalore", "jetbrains", "other", "self-hosted"]
not_affected_if: ["single-user", "version-2026.4-or-later"]
published_at: "2026-11-06T17:17:21+00:00"
first_seen_at: "2026-11-06T17:43:12+00:00"
updated_at: "2026-11-06T17:45:20+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123835", "first_seen_at": "2026-11-06T17:43:12+00:00"}]
exploit_sources: []
---

# JetBrains Datalore: init script upload race lets one user run code in another's computation

Link for people: https://infrastack.ai/live/CVE-2026-123835 (this .md is for agents)

Before version 2026.4 of JetBrains Datalore, a race condition in init script upload let code run inside another user's computation. An attacker who wins the race can execute code in a session that belongs to someone else.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed Datalore version against the fixed release, `2026.4`
- Look for a self-hosted Datalore deployment in your environment; unknown whether hosted Datalore is affected

## Fix

- Datalore: move to `2026.4` or later

## Timeline

- 2026-11-06T17:43:12+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123835

## From the sources

In JetBrains Datalore before 2026.4 code execution was possible in another user's computation via an init script upload race condition

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_