UBUNTU-CVE-2025-54121
Advisory lineage Upstream: 1 Downstream: 0
Upstream
Published: 21 Jul 2025, 20:15
Last modified:20 May 2026, 16:23
Vulnerability Summary
Overall Risk (default)
low
21/100 CVSS Score
5.3 MEDIUM
3.1 (osv_ubuntu)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected
Timeline
21 Jul 2025, 20:15
Published
Vulnerability first disclosed
20 May 2026, 16:23
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
Affected Systems
- ubuntu•starlette
all | all | all | all
References (6)
- https://ubuntu.com/security/CVE-2025-54121
- https://www.cve.org/CVERecord?id=CVE-2025-54121
- https://github.com/encode/starlette/security/advisories/GHSA-2c2j-9gv5-cj73
- https://github.com/encode/starlette/discussions/2927#discussioncomment-13721403
- https://github.com/encode/starlette/blob/fa5355442753f794965ae1af0f87f9fec1b9a3de/starlette/datastructures.py#L436C5-L447C14
- https://github.com/encode/starlette/commit/9f7ec2eb512fcc3fe90b43cb9dd9e1d08696bec1