CVE-2026-49384: CWE-79 in JetBrains PyCharm
A stored cross-site scripting (XSS) vulnerability exists in JetBrains PyCharm versions before 2025.3.4, specifically affecting Jupyter notebook Markdown cells. This vulnerability allows an attacker to inject malicious scripts that could execute in the context of the affected application. The vulnerability is tracked as CVE-2026-49384 and has a CVSS v3.1 base score of 6.1, indicating a medium severity level. No official patch or remediation guidance has been provided yet by the vendor. There are no known exploits in the wild at this time.
AI Analysis
Technical Summary
CVE-2026-49384 is a stored XSS vulnerability (CWE-79) in JetBrains PyCharm prior to version 2025.3.4. It affects the handling of Markdown cells in Jupyter notebooks, allowing malicious scripts to be stored and later executed when the notebook is viewed. The vulnerability has a CVSS 3.1 score of 6.1 (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N), indicating network attack vector, low attack complexity, no privileges required, user interaction required, scope changed, and low impact on confidentiality and integrity, with no impact on availability. The vendor has not yet provided an official fix or remediation level. The vulnerability is not related to a cloud service and no known exploits have been reported.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to execute arbitrary scripts in the context of the PyCharm application when a user opens a maliciously crafted Jupyter notebook Markdown cell. This could lead to partial compromise of confidentiality and integrity of data accessible within the application. There is no impact on availability. The vulnerability requires user interaction (opening the notebook) and has a medium severity rating.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should exercise caution when opening Jupyter notebooks from untrusted sources in PyCharm versions prior to 2025.3.4. Avoid opening notebooks containing Markdown cells from unknown or untrusted origins to reduce risk.
CVE-2026-49384: CWE-79 in JetBrains PyCharm
Description
A stored cross-site scripting (XSS) vulnerability exists in JetBrains PyCharm versions before 2025.3.4, specifically affecting Jupyter notebook Markdown cells. This vulnerability allows an attacker to inject malicious scripts that could execute in the context of the affected application. The vulnerability is tracked as CVE-2026-49384 and has a CVSS v3.1 base score of 6.1, indicating a medium severity level. No official patch or remediation guidance has been provided yet by the vendor. There are no known exploits in the wild at this time.
CVSS v3.1
Score 6.1medium
Affected software
pkg:github/jetbrains/PyCharmRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-49384 is a stored XSS vulnerability (CWE-79) in JetBrains PyCharm prior to version 2025.3.4. It affects the handling of Markdown cells in Jupyter notebooks, allowing malicious scripts to be stored and later executed when the notebook is viewed. The vulnerability has a CVSS 3.1 score of 6.1 (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N), indicating network attack vector, low attack complexity, no privileges required, user interaction required, scope changed, and low impact on confidentiality and integrity, with no impact on availability. The vendor has not yet provided an official fix or remediation level. The vulnerability is not related to a cloud service and no known exploits have been reported.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to execute arbitrary scripts in the context of the PyCharm application when a user opens a maliciously crafted Jupyter notebook Markdown cell. This could lead to partial compromise of confidentiality and integrity of data accessible within the application. There is no impact on availability. The vulnerability requires user interaction (opening the notebook) and has a medium severity rating.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should exercise caution when opening Jupyter notebooks from untrusted sources in PyCharm versions prior to 2025.3.4. Avoid opening notebooks containing Markdown cells from unknown or untrusted origins to reduce risk.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- JetBrains
- Date Reserved
- 2026-05-29T18:07:59.764Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a19dc13e29bf47b50ff88f5
Added to database: 05/29/2026, 18:33:55 UTC
Last enriched: 06/05/2026, 21:22:20 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 91
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.