# CVE-2026-123853: JetBrains IntelliJ IDEA code execution via JVM options in Safe Mode

Source: https://junglewise.ai/threats/cve-2026-123853-in-jetbrains-intellij-idea-before-2026-3-2026-2-2-code-execution  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-06. Updated: 2026-11-06  
License: CC BY 4.0 with a link back

CVE-2026-123853 · Severity: high · CVSS 7.8 · Published 2026-11-06

JetBrains IntelliJ IDEA is an integrated development environment used by software developers. A vulnerability in versions before 2026.3 and 2026.2.2 allows code execution even when Safe Mode is enabled, through malicious JVM options controlled by a project. An attacker who provides a crafted project could achieve arbitrary code execution on a developer's machine.

Technologies: [Jetbrains IntelliJ IDEA](https://junglewise.ai/threats/technologies/intellij-idea). Vendors: [Jetbrains](https://junglewise.ai/threats/vendors/jetbrains).

## Quick answers

**Is CVE-2026-123853 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-123853 being exploited in the wild.

**How severe is CVE-2026-123853?** High severity, with a CVSS score of 7.8, published 6 November 2026.

**Which products and versions are affected?** Jetbrains IntelliJ IDEA before 2026.3, 2026.2.2.

**Is there a fix for CVE-2026-123853?** Yes: fixed in 2026.3, 2026.2.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-123853 attacked?** It is attacked with local access, in a web application.

**Am I affected by CVE-2026-123853?** Check whether you run Jetbrains IntelliJ IDEA at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 2026.3, 2026.2.2

## Technical details

The vulnerability exists in the build process JVM option handling, where project-controlled parameters bypass Safe Mode restrictions. An attacker can craft a project with malicious JVM options that execute arbitrary code during the build process, circumventing the intended protections of Safe Mode. Exploitation requires the user to open and build a malicious project.

## Affected products

- JetBrains IntelliJ IDEA before 2026.3, 2026.2.2

## Timeline

- 2026-11-06: disclosed

## References

- [https://www.jetbrains.com/privacy-security/issues-fixed/](https://www.jetbrains.com/privacy-security/issues-fixed/)

## Related threats

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