# CVE-2026-123305: JetBrains IntelliJ IDEA path traversal in Dev Container archive unpacking

Source: https://junglewise.ai/threats/cve-2026-123305-in-jetbrains-intellij-idea-before-2026-3-path-traversal-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-2026-123305 · Severity: high · CVSS 7.5 · Published 2026-11-06

JetBrains IntelliJ IDEA is a code editor used by software developers. When a developer opens a Dev Container configuration from a remote source, the application unpacks archive files without properly validating their contents. An attacker can craft a malicious archive that writes files outside the intended directory, potentially overwriting important files or injecting malicious code into a developer's project.

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

## Quick answers

**Is CVE-2026-123305 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-123305 being exploited in the wild.

**How severe is CVE-2026-123305?** High severity, with a CVSS score of 7.5, published 6 November 2026.

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

**Is there a fix for CVE-2026-123305?** 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-2026-123305 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-123305?** 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

A path traversal vulnerability exists in the Dev Container archive unpacking functionality of IntelliJ IDEA. The vulnerability allows an attacker to craft a malicious archive containing relative path traversal sequences (e.g., "../") that bypass directory restrictions during extraction. This requires a developer to open or trust a remote Dev Container archive, and successful exploitation can result in arbitrary file write access within the developer's environment.

## 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/)

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