TI-2026-85999 Aliases CVE-2026-123840 GHSA-cw9v-29r9-xhg4

HTML injection in JetBrains IntelliJ IDEA Remote Development tabs

LOW 21CWE-80Published 2026-11-06 · Updated 2026-11-06

Key facts

Attack vector: Network
Privileges required: None
User interaction: Required
Attack complexity: High
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-80.

Summary

JetBrains IntelliJ IDEA before 2026.3 fails to neutralize script-related HTML tags in Remote Development editor tabs (CWE-80). A remote attacker can inject HTML into these tabs if a user interacts with crafted content, which affects confidentiality and integrity at a low level.

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

Description from the CNA

In JetBrains IntelliJ IDEA before 2026.3 hTML injection was possible in Remote Development editor tabs

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00199 9th percentileScored 2026-11-07

Fix Fixed IntelliJ IDEA (JetBrains): 2026.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

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

IntelliJ IDEA VendorJetBrains Affected before 2026.3 Fixed in 2026.3 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

Upgrade JetBrains IntelliJ IDEA to version 2026.3, which fixes this flaw.

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

Fix · CNA IntelliJ IDEA (JetBrains) Fixed in 2026.3

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
21 records Highest priority Priority LOW 21 LOW
Other records, highest priority first
- TI-2026-86000 Code execution via symlinks in IntelliJ IDEA settings archive importPriority LOW 35
- TI-2026-85997 Code execution in JetBrains IntelliJ IDEA Safe Mode via UI DesignerPriority LOW 35
- TI-2026-85846 Path traversal in JetBrains IntelliJ IDEA via Dev Container archivesPriority LOW 35
Show all 21 records →

Timeline

2026-11-06 Threatist record created from CVE-2026-123840
2026-11-06 Alias added: GHSA-cw9v-29r9-xhg4
2026-11-06 CISA SSVC decision points changed

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