How severe is CVE-2024-47874?

No CVSS score has been assigned to CVE-2024-47874 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2024-47874?

CVE-2024-47874 affects the following packages: starlette (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2024-47874?

Update starlette to 0.40.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-47874 is resolved across your whole dependency graph.

How do I detect CVE-2024-47874 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for starlette. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2024-47874 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2024-47874?

O3 pinpoints whether CVE-2024-47874 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2024-47874 actively exploited in the wild?

No public exploit code has been indexed for CVE-2024-47874 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What type of vulnerability is CVE-2024-47874?

CVE-2024-47874 is classified as CWE-770 (CWE-770). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2024-47874 published, and has it been updated?

CVE-2024-47874 was published on October 15, 2024 and was last updated on July 17, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

Not in CISA KEV

CVE-2024-47874

Fix: encode/starlette@fd038f3

CVE-2024-47874 is a CWE-770 vulnerability in starlette. O3 Security confirms whether CVE-2024-47874 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Starlette Denial of service (DoS) via multipart/form-data

Also known asGHSA-f96h-pmfr-66vwPYSEC-2026-1943

Published

Oct 15, 2024

Updated

Jul 17, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Jul 17, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🐍starlette

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`starlette`	all versions	0.40.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for starlette. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update starlette to 0.40.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-47874 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2024-47874 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2024-47874. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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

O3 Security · Impact-Aware SCA

Is CVE-2024-47874 in your dependencies?

O3 detects CVE-2024-47874 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works