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