CVE-2025-47287

A flaw was found in Tornado. This vulnerability can lead to a a denial of service by generating an extremely high volume of log entries.

This vulnerability marked as Important because it leverages the synchronous nature of the logging subsystem to induce a DoS condition. Specifically, malformed multipart/form-data payloads cause repeated, blocking log writes, which stall the event loop that underpins Tornado’s asynchronous architecture. Furthermore, because the vulnerable multipart parser is enabled by default, applications that are otherwise well-secured and do not even use file uploads can still be targeted unless they explicitly block these requests at a proxy.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.