CVE-20XX-?
agent?

CVE-2025-54121

5.3 MEDIUM 0.7% exploit odds Fix listed Denial of service Server

What it is

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.

At a glance

Exploitability
Can be exploited over the network without logging in. Limited direct impact.
Exploit odds
0.7% chance of exploitation in the next 30 days (EPSS).
Fix
A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

  1. PublishedDisclosed publicly on CVE.org and NVD
  2. Last updatedMost recent change to the record

Why it ranks here

Details

Published
Last modified
Exploit probability
0.7% · EPSS, next 30 days
Weakness
CWE-770 · Allocation without limits
Record status
Deferred

Attack profile CVSS 3.1 · 5.3

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low
Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2025-54121.md and follow it. Check whether this project is affected by CVE-2025-54121. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record