Quick answers
- Is CVE-2026-123306 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-123306 being exploited in the wild.
- How severe is CVE-2026-123306?
- High severity, with a CVSS score of 7.4, published 6 November 2026.
- Which products and versions are affected?
- Jetbrains IntelliJ IDEA before 2026.3.
- Is there a fix for CVE-2026-123306?
- Yes: fixed in 2026.3. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-123306 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-123306?
- 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
Technical details
The vulnerability stems from improper certificate validation checks in IntelliJ IDEA's headless execution mode. An attacker with network access could inject a malicious certificate into the trust store during headless runs, enabling interception of encrypted communications. The flaw affects versions before 2026.3 and requires no authentication or user interaction beyond running the tool in headless mode.
Affected products
- JetBrains IntelliJ IDEA before 2026.3
Timeline
- 2026-11-06: disclosed