CVE-2026-123831: JetBrains CLion · Untrusted Functionality Inclusion
Affects JetBrains CLionSource CVE Database V5
Not known to be exploited · CVSS 9.6 Critical : upgrade to 2026.2 as a priority.
Data as of 6 Nov 2026, 17:47 UTC
Thin evidence
One scorer or none| CNA (JetBrains) | CVSS 3.1 | 9.6 |
|---|
- Patch
- Available – fixed in 2026.2
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade JetBrains CLion to 2026.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| JetBrainsCLion | Affected
| Fixed in
|
AI-suggested
Upgrade JetBrains CLion to version 2026.2 or later, where this vulnerability is fixed. No other mitigation or temporary workaround is indicated by the vendor advisory.
Description
CVE-2026-123831 is a critical vulnerability in JetBrains CLion before version 2026.2 that allows code execution in Safe Mode via Meson project settings. The flaw involves inclusion of functionality from an untrusted control sphere (CWE-829). It has a high CVSS score of 9.6, indicating severe impact on confidentiality, integrity, and availability. The issue is fixed in version 2026.2.