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JetBrains IntelliJ IDEA missing TLS certificate host name verification

Priority LOW 34CWE-297Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

In JetBrains IntelliJ IDEA before 2026.3, host name verification was missing for server TLS certificates, so a certificate for another host could be accepted. The weakness is classified as CWE-297, Improper Validation of Certificate with Host Mismatch. CVSS 3.1 rates it 7.4 (HIGH), with high confidentiality and integrity impact and no availability impact.

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

Description from the CNA

In JetBrains IntelliJ IDEA before 2026.3 host name verification was missing for server TLS certificates

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00201 10th 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
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
JetBrainsIntelliJ IDEAbefore 2026.32026.3Patch availableCNA
  • 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.

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

Remediation

Update JetBrains IntelliJ IDEA to version 2026.3 or later, where host name verification for server TLS certificates is present.

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 ·

    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

Timeline

  1. 2026-11-06 Threatist record created from CVE-2026-123848
  2. 2026-11-06 Alias added: GHSA-66w3-pp4w-4974
  3. 2026-11-06 CISA SSVC decision points changed
  4. 2026-11-06 Priority changed: MEDIUM → LOW
  5. 2026-11-07 CISA SSVC decision points changed

References

  • 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