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PatchSiren cyber security CVE debrief

CVE-2026-49367 JetBrains CVE debrief

A command execution vulnerability exists in JetBrains IntelliJ IDEA versions prior to 2026.1.1. The flaw allows command execution via the guest user account, presenting a significant security risk in multi-user or shared environments where guest access may be enabled. The vulnerability is classified as HIGH severity with a CVSS score of 8.0. The attack vector is network-based with low attack complexity, requiring low privileges and user interaction. The confidentiality, integrity, and availability impacts are all rated HIGH. The underlying weakness is categorized as CWE-862 (Missing Authorization). JetBrains has addressed this issue in version 2026.1.1. Organizations should prioritize updating affected installations, particularly those with guest account functionality enabled or exposed to untrusted users.

Vendor
JetBrains
Product
IntelliJ IDEA
CVSS
HIGH 8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-29
Original CVE updated
2026-05-29
Advisory published
2026-05-29
Advisory updated
2026-05-29

Who should care

Development teams, DevSecOps engineers, and organizations using JetBrains IntelliJ IDEA in shared or multi-user configurations, particularly those with guest access enabled.

Technical summary

The vulnerability permits arbitrary command execution through the guest user account in IntelliJ IDEA. The network-accessible attack surface, combined with low privilege requirements and high impact across confidentiality, integrity, and availability, makes this a critical patching priority for development environments. The fix in 2026.1.1 addresses the missing authorization controls (CWE-862) that allowed guest users to execute commands.

Defensive priority

HIGH

Recommended defensive actions

  • Upgrade JetBrains IntelliJ IDEA to version 2026.1.1 or later
  • Review and disable guest user accounts if not required
  • Audit access logs for suspicious activity from guest accounts
  • Restrict network access to IntelliJ IDEA instances where possible
  • Verify patch deployment across all developer workstations and shared environments

Evidence notes

Vulnerability confirmed through official JetBrains security advisory and NVD entry. CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H. Weakness: CWE-862 (Missing Authorization).

Official resources

2026-05-29T19:16:26.440Z