# CVE-2026-123276: JetBrains CLion code execution in Safe Mode via GDB debug profile

Source: https://junglewise.ai/threats/cve-2026-123276-in-jetbrains-clion-before-2026-3-2026-2-4-1-code-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-2026-123276 · Severity: high · CVSS 7.8 · Published 2026-11-06

JetBrains CLion is an integrated development environment for C and C++ programming. A vulnerability in its Safe Mode allows an attacker to execute arbitrary code by providing a specially crafted GDB server debug profile, potentially compromising developer machines and source code.

Technologies: [Jetbrains CLion](https://junglewise.ai/threats/technologies/clion). Vendors: [Jetbrains](https://junglewise.ai/threats/vendors/jetbrains).

## Quick answers

**Is CVE-2026-123276 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-123276 being exploited in the wild.

**How severe is CVE-2026-123276?** High severity, with a CVSS score of 7.8, published 6 November 2026.

**Which products and versions are affected?** Jetbrains CLion before 2026.3, before 2026.2.4.1.

**Is there a fix for CVE-2026-123276?** Yes: fixed in CLion 2026.3, 2026.2.4.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-123276 attacked?** It is attacked with local access, in a web application.

**Am I affected by CVE-2026-123276?** Check whether you run Jetbrains CLion 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 CLion 2026.3, 2026.2.4.1

## Technical details

CLion's Safe Mode does not properly validate GDB server debug profiles, allowing code execution through a crafted profile submitted to an IDE instance in Safe Mode. The vulnerability requires the attacker to provide malicious input via a debug configuration but bypasses the safety mechanisms intended to prevent execution during Safe Mode startup. A fix is available in CLion 2026.3 and 2026.2.4.1.

## Affected products

- JetBrains CLion before 2026.3, before 2026.2.4.1

## 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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- [JetBrains IDEs embedded browser trusted revoked certificates](https://junglewise.ai/threats/cve-2026-118696-in-jetbrains-intellij-idea-pycharm-phpstorm-rubymine-and)