CVE-2024-47874

unknown
Published 2024-10-15 · Modified 2026-02-04
CVSS v3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N
CVSS v2
VIR risk

Description

Starlette is an Asynchronous Server Gateway Interface (ASGI) framework/toolkit. Prior to version 0.40.0, Starlette treats `multipart/form-data` parts without a `filename` as text form fields and buffers those in byte strings with no size limit. This allows an attacker to upload arbitrary large form fields and cause Starlette to both slow down significantly due to excessive memory allocations and copy operations, and also consume more and more memory until the server starts swapping and grinds to a halt, or the OS terminates the server process with an OOM error. Uploading multiple such requests in parallel may be enough to render a service practically unusable, even if reasonable request size limits are enforced by a reverse proxy in front of Starlette. This Denial of service (DoS) vulnerability affects all applications built with Starlette (or FastAPI) accepting form requests. Verison 0.40.0 fixes this issue.

Predictions

Exploit likelihood
30%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2024-47874

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2024-47874.html

OS impact

OSVersionStatusFixed in
suse slesaffected
debian debianbullseyeaffected
debian debianforkyfixed0.41.0-1
debian debiansidfixed0.41.0-1
debian debiantrixiefixed0.41.0-1
debian debianbookwormfixed0.26.1-1+deb12u1

Package impact

EcosystemPackageVulnerableFixed
python PyPIstarlette<0.40.00.40.0

References

Verify integrity in audit chain (admin only). AS-IS.