CVE-2026-86503 in IntelliJ IDEA
Summary
by MITRE • 09/07/2026
In JetBrains IntelliJ IDEA before 2026.2.2 opening an untrusted project could trigger SSRF via Kubernetes spec-source URL fetching
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Analysis
by VulDB Data Team • 09/07/2026
The vulnerability identified in versions of JetBrains IntelliJ IDEA prior to version 2026.2.2 represents a significant security risk associated with the handling of external resources during project initialization, specifically within the context of cloud-native development workflows involving Kubernetes specifications. This flaw is classified as a Server-Side Request Forgery (SSRF) vulnerability, which allows an attacker who can influence or control the input parameters for opening a project to force the application to make HTTP requests to arbitrary destinations under the network environment where IntelliJ IDEA is running. The specific attack vector involves the manipulation of Kubernetes specification sources, where the IDE attempts to fetch and parse configuration files from URLs provided by the user or embedded within the project structure.
When a developer opens an untrusted project that contains references to external Kubernetes manifests or configurations, IntelliJ IDEA may automatically attempt to resolve these resources by fetching them via HTTP requests. Due to insufficient validation of the target URL scheme and host address, the application does not adequately restrict access to internal network ranges, local loopback interfaces, or other sensitive infrastructure endpoints. This lack of input sanitization enables an attacker to craft a malicious project file that directs the IDE to request data from internal services such as metadata servers, database instances, or administrative consoles that are otherwise inaccessible from external networks but reachable from the developer's machine.
The operational impact of this SSRF vulnerability is multifaceted and potentially severe depending on the network topology surrounding the development environment. Attackers can leverage this flaw to perform port scanning against internal hosts by observing differences in response times or error messages, thereby mapping out the internal network structure. Furthermore, if sensitive services are running without authentication or with weak credentials on accessible ports, the attacker could retrieve confidential data such as database dumps, configuration secrets, or application logs. In cloud environments where instance metadata services are exposed to local interfaces, this vulnerability can be exploited to steal temporary security credentials and API keys associated with the host machine, leading to a complete compromise of the underlying infrastructure.
This issue aligns closely with CWE-918, which describes Server-Side Request Forgery flaws resulting from web applications fetching remote resources without validating user-supplied input. Additionally, it maps to MITRE ATT&CK technique T1571, specifically the component related to Non-Standard Ports or protocols if exploited against internal services that do not use standard HTTP ports, and potentially T1046 for Network Service Discovery through active probing of internal networks via the forged requests. The vulnerability underscores the risks inherent in IDEs acting as complex clients that interact with external resources on behalf of users, particularly when those interactions are automated during project loading processes without strict security boundaries.
Mitigation strategies primarily involve upgrading to JetBrains IntelliJ IDEA version 2026.2.2 or later, where this specific SSRF vector has been addressed through improved URL validation and restriction mechanisms. For organizations unable to immediately patch all endpoints, implementing network-level controls such as egress filtering can provide a layer of defense by blocking outbound connections from the development workstation to sensitive internal IP ranges unless explicitly authorized. Security teams should also enforce strict code review policies for shared project templates or plugins that might introduce untrusted Kubernetes configurations into local environments. Additionally, enabling IDE security features that warn users about external resource fetching during project initialization can help mitigate exploitation attempts in transitional periods before full patch deployment is achieved across the development infrastructure.