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TI-2026-85990 Aliases CVE-2026-123831GHSA-3hcx-x64h-4m2v

Code execution in JetBrains CLion Safe Mode through Meson settings

Priority MEDIUM 43CWE-829Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-829.

Summary

JetBrains CLion before 2026.2, 2026.1.4 can run code in Safe Mode through Meson project settings. The flaw, CWE-829, lets untrusted Meson project settings load and run functionality that Safe Mode should block. A remote attacker without privileges can execute code, but a user must interact with the attack.

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

Description from the CNA

In JetBrains CLion before 2026.2, 2026.1.4 code execution was possible in Safe Mode via Meson project settings

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0045 39th percentileScored 2026-11-07
Fix Fixed CLion (JetBrains): 2026.2, 2026.1.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

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

Affected products

VendorProductAffected versionsFixed inStatusSource
JetBrainsCLionbefore 2026.2, 2026.1.42026.2, 2026.1.4Patch availableCNA
  • CLion VendorJetBrains Affected before 2026.2, 2026.1.4 Fixed in 2026.2, 2026.1.4 Patch available CNA

Remediation

Upgrade JetBrains CLion to 2026.2 or 2026.1.4.

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

  • Fix · CNA CLion (JetBrains) Fixed in 2026.2, 2026.1.4

Timeline

  1. 2026-11-06 Threatist record created from CVE-2026-123831
  2. 2026-11-06 CISA SSVC decision points changed
  3. 2026-11-06 Alias added: GHSA-3hcx-x64h-4m2v
  4. 2026-11-07 CISA SSVC decision points changed

References

Other 1

  • 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