Cross-site scripting in PyCharm - CVE-2026-49384
Published: August 17, 2026
Vulnerability identifier: #VU143812
CSH Severity: Low
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-49384
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to execute arbitrary script code in a victim's browser.
The vulnerability exists due to cross-site scripting in Jupyter notebook Markdown cells when rendering stored Markdown content. A remote user can inject a malicious script into a Markdown cell to execute arbitrary script code in a victim's browser.
Affected software
PyCharm
How to mitigate CVE-2026-49384
Install security update from vendor's website.
PyCharm - update to 2025.3.4