CVE-2025-54121 — Allocation of Resources Without Limits or Throttling in Starlette
Severity
5.3MEDIUMNVD
EPSS
0.2%
top 54.63%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
Timeline
PublishedJul 21
Description
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_me…
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LExploitability: 3.9 | Impact: 1.4
Affected Packages4 packages
🔴Vulnerability Details
3GHSA▶
Starlette has possible denial-of-service vector when parsing large files in multipart forms↗2025-07-21
OSV▶
Starlette has possible denial-of-service vector when parsing large files in multipart forms↗2025-07-21
OSV▶
CVE-2025-54121: Starlette is a lightweight ASGI (Asynchronous Server Gateway Interface) framework/toolkit, designed for building async web services in Python↗2025-07-21