CVE-2026-22745 in Spring Framework
Summary
by MITRE • 04/29/2026
Spring MVC and WebFlux applications are vulnerable to Denial of Service attacks when resolving static resources.
More precisely, an application can be vulnerable when all the following are true:
* the application is using Spring MVC or Spring WebFlux * the application is serving static resources from the file system * the application is running on a Windows platform
When all the conditions above are met, the attacker can send malicious requests that are slow to resolve and that can keep HTTP connections in use. This can cause a Denial of Service on the application.
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Analysis
by VulDB Data Team • 05/17/2026
This vulnerability represents a critical denial of service condition affecting spring framework applications running on windows platforms. The flaw stems from how spring mvc and webflux handle static resource resolution when serving files from the file system, creating an opportunity for attackers to exploit resource exhaustion through carefully crafted requests. The vulnerability is specifically tied to the interaction between spring's resource handling mechanisms and windows file system operations, making it platform-dependent and particularly dangerous in production environments where resource constraints are already tight.
The technical mechanism behind this vulnerability involves the way spring applications process static resource requests on windows systems. When an application serves static content from the file system and operates on windows platforms, the resource resolution process becomes susceptible to time-consuming operations that can be exploited by attackers. The malicious requests leverage path traversal patterns or complex file system operations that cause the application to spend excessive time resolving file paths, effectively consuming http connections and thread resources. This behavior creates a resource starvation condition where legitimate requests cannot be processed due to the exhaustion of available connection slots and processing capacity. The vulnerability aligns with common attack patterns documented in the attack technique framework under the category of resource exhaustion attacks.
The operational impact of this vulnerability is severe and can lead to complete service unavailability for applications affected by the condition. Attackers can maintain persistent connections while consuming system resources, making the application unable to serve legitimate requests. This creates a cascading effect where even normal user traffic becomes impacted as the application's connection pool becomes depleted and processing threads are consumed by the malicious requests. The vulnerability can be particularly devastating in high-traffic environments where connection limits are already near capacity. Organizations running spring applications on windows servers face significant risk of operational disruption and potential financial loss due to the denial of service condition.
Mitigation strategies should focus on both immediate protective measures and long-term architectural improvements. The most direct approach involves updating spring framework versions to patched releases that address the resource resolution behavior on windows platforms. Organizations should implement connection timeouts and resource limits to prevent attackers from consuming excessive connections. Network-level protections including rate limiting and connection tracking can help detect and block malicious patterns. Additionally, application-level configurations should restrict static resource access to known directories and implement proper path validation to prevent path traversal attacks. The vulnerability demonstrates the importance of platform-specific security considerations in framework-level implementations and aligns with the principle of least privilege in access control. Organizations should also consider implementing monitoring and alerting systems to detect unusual connection patterns that might indicate exploitation attempts. The fix addresses the underlying CWE categories related to resource management and path traversal vulnerabilities, providing a comprehensive solution that protects against both current and potential future exploitation vectors.