What is CVE-2026-123306?

CVE-2026-123306 is a high-severity vulnerability in Jetbrains Intellij Idea, classified under Improper Certificate Validation. CVSS score: 7.4/10. Published 2026-11-06.

How severe is CVE-2026-123306?

High severity. CVSS v3 base score is 7.4 out of 10.

Vulnerability in Jetbrains Intellij Idea

CVE-2026-123306

In JetBrains IntelliJ IDEA before 2026.3 improper checks allowed server certificates to be added to the trust store during headless runs

Vulnerability class: Improper Certificate Validation

Published 2026-11-06 · last modified 2026-11-07.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.002 (10.0th percentile), scored 2026-11-09.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 10th percentile — 10.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Jetbrains Intellij Idea

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

www.jetbrains.com/privacy-security/issues-fixed/

Frequently asked questions

What is CVE-2026-123306?: CVE-2026-123306 is a high-severity vulnerability in Jetbrains Intellij Idea, classified under Improper Certificate Validation. CVSS score: 7.4/10. Published 2026-11-06.
How severe is CVE-2026-123306?: High severity. CVSS v3 base score is 7.4 out of 10.