CVE-2026-64813: 
JetBrains IntelliJ IDEA vulnerability analysis and mitigation

CVE-2026-64813 is an authorization bypass vulnerability in JetBrains IntelliJ IDEA that allows unauthenticated remote attackers to perform unauthorized settings modification within a Remote Development session. It affects all versions of IntelliJ IDEA before 2026.2 and was published on July 23, 2026, with a patch released in version 2026.2. The vulnerability carries a CVSS v3.1 base score of 10.0 (Critical), assigned by JetBrains (JetBrains Advisory, NVD).

The root cause is classified as CWE-602 (Client-Side Enforcement of Server-Side Security), meaning the application relies on client-side controls to enforce security restrictions that should be validated server-side. In the context of IntelliJ IDEA's Remote Development feature, security checks governing settings modification are insufficiently enforced on the server, allowing a network-accessible attacker to bypass authorization entirely. The attack requires no privileges, no user interaction, and has a changed scope, indicating impact can extend beyond the directly vulnerable component. CISA's SSVC assessment classifies the vulnerability as automatable with total technical impact (NVD, JetBrains Advisory).

Successful exploitation allows an unauthenticated remote attacker to modify IDE settings within an active Remote Development session, with potential high impact across confidentiality, integrity, and availability. Because the CVSS scope is marked as "Changed," the vulnerability can affect resources beyond the IntelliJ IDEA process itself — for example, altering build configurations, proxy settings, or plugin sources could facilitate code injection, supply chain compromise, or persistent access to developer workstations and connected infrastructure. The total technical impact classification by CISA underscores the severity of a full settings takeover in a developer environment (NVD, GBHackers).

As of the time of disclosure, there is no public proof-of-concept exploit and no evidence of in-the-wild exploitation (Feedly). CISA's SSVC assessment rates the vulnerability as "automatable" with exploitation status of "none," indicating it has not been observed being actively exploited but could be scripted at scale. The EPSS score is approximately 0.39%, reflecting a currently low but non-negligible probability of exploitation in the near term. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog at this time (NVD).

1. Reconnaissance: Identify exposed IntelliJ IDEA Remote Development sessions accessible over the network, using port scanning or service fingerprinting tools targeting default Remote Development ports.
2. Confirm vulnerable version: Verify the target is running IntelliJ IDEA prior to version 2026.2, as later versions contain the patch.
3. Craft unauthorized request: Send a crafted network request to the Remote Development session endpoint that manipulates IDE settings — exploiting the lack of server-side authorization checks (CWE-602) to bypass access controls.
4. Modify settings: Alter IDE configuration such as build tool paths, plugin repositories, proxy settings, or run configurations to introduce malicious behavior (e.g., pointing to a rogue plugin server or modifying compiler arguments).
5. Achieve objective: Leverage modified settings to execute malicious code during the next build or IDE action, establish persistence, or pivot to connected systems and repositories (NVD, GBHackers).

• Network: Unexpected or unauthorized connections to IntelliJ IDEA Remote Development ports from external or untrusted IP addresses; unusual API calls to Remote Development session management endpoints.
• Logs: IntelliJ IDEA logs showing settings changes without corresponding authenticated user actions; entries reflecting configuration modifications during periods of no active developer session.
• File System: Unexpected changes to IDE configuration files (e.g., .idea/ directory contents, workspace.xml, plugin configuration files) without corresponding developer activity.
• Process: Unusual child processes spawned from the IntelliJ IDEA backend process following a Remote Development session; unexpected plugin installations or updates.

JetBrains has released a fix in IntelliJ IDEA version 2026.2; upgrading to this version or later is the primary recommended remediation (JetBrains Advisory). For environments where immediate patching is not feasible, restrict network access to Remote Development sessions using firewall rules or VPN, limiting exposure to trusted networks and authenticated users only. Organizations should also audit current Remote Development session configurations for unauthorized changes as a precautionary measure (Feedly).

Security news outlets including GBHackers, CyberSecurityNews, and SecurityOnline covered the vulnerability as part of a broader JetBrains patch release addressing multiple critical flaws in IntelliJ IDEA and TeamCity (GBHackers, CyberSecurityNews, SecurityOnline). The Hacker News included it in a weekly security recap, highlighting the CVSS 10.0 score as notable (The Hacker News). Community reaction has focused on the maximum severity score and the risk to developer environments, though no significant researcher controversy or threat actor attribution has emerged.