CVE-2026-123848: JetBrains IntelliJ IDEA · Improper Validation of Certificate with Host Mismatch
Affects JetBrains IntelliJ IDEASource CVE Database V5
Not known to be exploited · CVSS 7.4 High : upgrade to 2026.3 soon.
Data as of 6 Nov 2026, 17:40 UTC
Thin evidence
One scorer or none| CNA (JetBrains) | CVSS 3.1 | 7.4 |
|---|
- Patch
- Available – fixed in 2026.3
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NExploitation 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 IntelliJ IDEA to 2026.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| JetBrainsIntelliJ IDEA | Affected
| Fixed in
|
AI-suggested
Users should upgrade to JetBrains IntelliJ IDEA version 2026.3 or later, where host name verification for TLS certificates is properly implemented. No other mitigations are indicated by the vendor advisory.
Description
CVE-2026-123848 is a vulnerability in JetBrains IntelliJ IDEA prior to version 2026.3 where host name verification was missing for server TLS certificates. This improper validation of certificates (CWE-297) could allow an attacker to present a TLS certificate that does not match the server's host name, potentially enabling man-in-the-middle attacks. The issue has been fixed in version 2026.3.