TI-2026-85850 Aliases CVE-2026-123309 GHSA-4rqw-p72p-2m5j

Cross-site scripting in JetBrains IntelliJ IDEA Markdown preview

LOW 27CWE-79Published 2026-11-06 · Updated 2026-11-06

Key facts

Attack vector: Network
Privileges required: None
User interaction: Required
Attack complexity: Low
Impact type: Cross-site scripting
Confidentiality · integrity · availability: Low · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

JetBrains IntelliJ IDEA before 2026.3, 2026.2.4 is affected. Stored input in the Markdown preview of the built-in web server is not neutralized before it is placed in a web page (CWE-79), so scripts can run in the page. An unauthenticated remote attacker can exploit this when a user interacts with the affected page.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

In JetBrains IntelliJ IDEA before 2026.3, 2026.2.4 stored XSS was possible on the built-in web server via Markdown preview

Why it matters now

EPSS 0.0023 13th percentileScored 2026-11-07

Fix Fixed IntelliJ IDEA (JetBrains): 2026.3, 2026.2.4

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
JetBrains	IntelliJ IDEA	before 2026.3, 2026.2.4	2026.3, 2026.2.4	Patch available	CNA

IntelliJ IDEA VendorJetBrains Affected before 2026.3, 2026.2.4 Fixed in 2026.3, 2026.2.4 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:jetbrains:intellij_idea::::::::	—	—	JetBrains

cpe:2.3:a:jetbrains:intellij_idea:*:*:*:*:*:*:*:* Versions — — ·JetBrains

Remediation

Fixed in IntelliJ IDEA 2026.3 and 2026.2.4. Upgrade to one of these versions.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Fix · CNA IntelliJ IDEA (JetBrains) Fixed in 2026.3, 2026.2.4

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2026-11-06
JetBrains IntelliJ IDEA 2026.3, 2026.2.4
6 records Highest priority Priority LOW 6 LOW
Other records, highest priority first
- TI-2026-85835 Code execution in IntelliJ IDEA via Terraform tool path settingPriority LOW 35
- TI-2026-85848 Server-side request forgery in JetBrains IntelliJ IDEAPriority LOW 32
- TI-2026-85852 Command execution in JetBrains IntelliJ IDEA via Markdown previewPriority LOW 25
Show all 6 records →

Timeline

2026-11-06 Threatist record created from CVE-2026-123309
2026-11-06 Alias added: GHSA-4rqw-p72p-2m5j
2026-11-08 Priority changed: MEDIUM → LOW

References

Other 1

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

TI-2026-45031 Deserialization of untrusted data in JetBrains TeamCity KEVCVSS 3.1CRITICAL 9.8
TI-2024-18053 In JetBrains TeamCity before 2023.11.4 authentication bypass allowing to perform admin actions was possible KEVCVSS 3.1CRITICAL 9.8
TI-2023-22884 In JetBrains TeamCity before 2023.05.4 authentication bypass leading to RCE on TeamCity Server was possible KEVCVSS 3.1CRITICAL 9.8
TI-2024-18054 In JetBrains TeamCity before 2023.11.4 path traversal allowing to perform limited admin actions was possible KEVCVSS 3.1HIGH 7.3
TI-2024-15905 In JetBrains TeamCity before 2023.11.3 authentication bypass leading to RCE was possible CVSS 3.1CRITICAL 9.8
TI-2024-24589 Insufficiently protected credentials in JetBrains IntelliJ IDEA CVSS 3.1CRITICAL 9.3

See all 787 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences