CVE-2025-54121
Starlette has possible denial-of-service vector when parsing large files in multipart forms
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Starlette has possible denial-of-service vector when parsing large files in multipart forms
Starlette is a lightweight ASGI (Asynchronous Server Gateway Interface) framework/toolkit, designed for building async web services in Python. In versions 0.47.1 and below, when parsing a multi-part form with large files (greater than the default max spool size) starlette will block the main thread to roll the file over to disk. This blocks the event thread which means the application can't accept new connections. The UploadFile code has a minor bug where instead of just checking for self._in_memory, the logic should also check if the additional bytes will cause a rollover. The vulnerability is fixed in version 0.47.2.
Reserved 2025-07-16 | Published 2025-07-21 | Updated 2025-07-21 | Assigner GitHub_MCWE-770: Allocation of Resources Without Limits or Throttling
github.com/...rlette/security/advisories/GHSA-2c2j-9gv5-cj73
github.com/...ommit/9f7ec2eb512fcc3fe90b43cb9dd9e1d08696bec1
github.com/...af0f87f9fec1b9a3de/starlette/datastructures.py
github.com/encode/starlette/discussions/2927
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