CVE-2025-54121

Aliases:GHSA-2c2j-9gv5-cj73PYSEC-2026-1941DEBIAN-CVE-2025-54121
Advisory lineage Upstream: 0 Downstream: 6
Deferred
Published: 21 Jul 2025, 20:06
Last modified:22 Jul 2025, 19:54

Vulnerability Summary

Overall Risk (default)
low
21/100
CVSS Score
5.3 MEDIUM
v3.1 (cve.org)
EPSS Score
0.53% LOW
1% probability +0.44%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

21 Jul 2025, 20:06
Published
Vulnerability first disclosed
22 Jul 2025, 19:54
Last Modified
Vulnerability information updated

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_memory, the logic should also check if the additional bytes will cause a rollover. The vulnerability is fixed in version 0.47.2.

CVSS Metrics

  • v3.1•MEDIUM•Score: 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS Trends

Current EPSS score: 0.53%• Percentile: 43%

Techniques & Countermeasures

  • CWE-770•Allocation of Resources Without Limits or Throttling

    The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

Affected Systems

  • debian•starlette

    all | < 0.26.1-1+deb12u1 | < 0.46.1-3 | < 0.46.1-3

  • encode•starlette

    < 0.47.2

  • PyPI•starlette

    < 0.47.2

References (9)