Description

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.

Affected Spring Products and Versions

Spring Framework:

• 7.0.0 - 7.0.6
• 6.2.0 - 6.2.17
• 6.1.0 - 6.1.26
• 5.3.0 - 5.3.47

Older, unsupported versions are also vulnerable.

Mitigation

Users of affected versions should upgrade to the corresponding fixed version.

No further mitigation steps are necessary.

Credit

This issue was responsibly reported by Bocheng Xiang (@crispr) from Fudan University.

References

• https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L&version=3.1

History

• 2026-04-17: Initial vulnerability report published.