What is CVE-2026-123854?

CVE-2026-123854 is a medium-severity vulnerability in Jetbrains Pycharm, classified under Inclusion of Functionality from Untrusted Control Sphere. CVSS score: 5.5/10. Published 2026-11-06.

How severe is CVE-2026-123854?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Vulnerability in Jetbrains Pycharm

CVE-2026-123854

In JetBrains PyCharm before 2026.3 code execution was possible in Safe Mode via a crafted Jupyter notebook widget module

Published 2026-11-06 · last modified 2026-11-08.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Jetbrains Pycharm

Weakness classification (CWE)

CWE-829 — Inclusion of Functionality from Untrusted Control Sphere

References

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

Frequently asked questions

What is CVE-2026-123854?: CVE-2026-123854 is a medium-severity vulnerability in Jetbrains Pycharm, classified under Inclusion of Functionality from Untrusted Control Sphere. CVSS score: 5.5/10. Published 2026-11-06.
How severe is CVE-2026-123854?: Medium severity. CVSS v3 base score is 5.5 out of 10.