Description

Spring WebFlux applications are vulnerable to Denial of Service (DoS) attacks when processing multipart requests.

More precisely, an application can be vulnerable when all the following are true:

• The application uses Spring WebFlux.
• The application implements a web endpoint that receives multipart requests.

When all the conditions above are met, an attacker can send malicious multipart requests that can leak memory, potentially leading to Denial of Service in the application.

Affected Spring Products and Versions

Spring Framework:

• 7.0.0 - 7.0.7
• 6.2.0 - 6.2.18
• 6.1.0 - 6.1.27
• 5.3.0 - 5.3.48

Versions that are no longer supported are also affected.

Mitigation

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

No further mitigation steps are necessary.

Credit

This issue was discovered internally.

References

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

History

• 2026-06-08: Initial vulnerability report published.