# CVE-2026-123847: JetBrains IntelliJ IDEA command execution via control characters in terminal completion

Source: https://junglewise.ai/threats/cve-2026-123847-in-jetbrains-intellij-idea-before-2026-3-command-execution-was  
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-2026-123847 · Severity: medium · CVSS 5.3 · Published 2026-11-06

JetBrains IntelliJ IDEA is an integrated development environment used by software developers to write code. A vulnerability in the terminal command completion feature allows an attacker to execute arbitrary commands by injecting control characters into completion suggestions, potentially compromising the developer's system and any code or credentials accessible through their IDE.

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

## Quick answers

**Is CVE-2026-123847 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-123847 being exploited in the wild.

**How severe is CVE-2026-123847?** Medium severity, with a CVSS score of 5.3, published 6 November 2026.

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

**Is there a fix for CVE-2026-123847?** Yes: fixed in IntelliJ IDEA 2026.3. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-123847 attacked?** It is attacked with local access, in a web application.

**Am I affected by CVE-2026-123847?** 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 IntelliJ IDEA 2026.3

## Technical details

The vulnerability exists in the terminal command completion feature of IntelliJ IDEA, where insufficient validation of control characters in completion suggestions allows command injection. An attacker can craft malicious completion entries containing control characters to execute arbitrary system commands when a developer interacts with the terminal completion interface, gaining code execution within the context of the IDE user.

## Affected products

- JetBrains IntelliJ IDEA before 2026.3

## Timeline

- 2026-11-06: disclosed

## References

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

## Related threats

- [JetBrains IntelliJ IDEA code execution via JVM options in Safe Mode](https://junglewise.ai/threats/cve-2026-123853-in-jetbrains-intellij-idea-before-2026-3-2026-2-2-code-execution)
- [JetBrains IntelliJ IDEA code execution via Terraform File Watchers](https://junglewise.ai/threats/cve-2026-123849-in-jetbrains-intellij-idea-before-2026-3-code-execution-was)
- [JetBrains IntelliJ IDEA TLS hostname verification missing](https://junglewise.ai/threats/cve-2026-123848-in-jetbrains-intellij-idea-before-2026-3-host-name-verification)
- [JetBrains IntelliJ IDEA blind SSRF in JSON Schema validation](https://junglewise.ai/threats/cve-2026-123846-in-jetbrains-intellij-idea-before-2026-3-blind-ssrf-was-possible)
- [JetBrains IntelliJ IDEA server-side request forgery in plugin repositories](https://junglewise.ai/threats/cve-2026-123844-in-jetbrains-intellij-idea-before-2026-3-ssrf-was-possible-via)