---
id: "CVE-2026-123831"
page: "https://infrastack.ai/live/CVE-2026-123831"
kind: "vulnerability"
aliases: ["CVE-2026-123831"]
title: "CLion: Meson project settings run code even in Safe Mode"
severity: "critical"
cvss: 9.6
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["c++", "clion", "developer-tools", "jetbrains", "meson", "other"]
not_affected_if: ["trusted-projects-only", "updated-ide"]
published_at: "2026-11-06T17:17:21+00:00"
first_seen_at: "2026-11-06T17:43:12+00:00"
updated_at: "2026-11-06T17:44:50+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123831", "first_seen_at": "2026-11-06T17:43:12+00:00"}]
exploit_sources: []
---

# CLion: Meson project settings run code even in Safe Mode

Link for people: https://infrastack.ai/live/CVE-2026-123831 (this .md is for agents)

JetBrains CLion, a C and C++ IDE, could run attacker-supplied code through Meson project settings even when Safe Mode was on. An attacker who gets a developer to open a crafted project can run code on that developer's machine.

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

## How to check

- Check the installed CLion version under Help > About in the IDE.
- Look for a Meson build configuration in projects you open from untrusted sources.

## Fix

- CLion before `2026.2` and `2026.1.4` is affected; move to `2026.2` or `2026.1.4` or later.

## Timeline

- 2026-11-06T17:43:12+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123831

## From the sources

In JetBrains CLion before 2026.2, 
2026.1.4 code execution was possible in Safe Mode via Meson project settings

---

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