What’s Vulnerable › Vulnerabilities

CVE-2024-24762: python-multipart vulnerable to content-type header Regular expression Denial of Service

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2024-02-05 · updated 2026-06-17
• Weakness: CWE-400

Description

`python-multipart` is a streaming multipart parser for Python. When using form data, `python-multipart` uses a Regular Expression to parse the HTTP `Content-Type` header, including options. An attacker could send a custom-made `Content-Type` option that is very difficult for the RegEx to process, consuming CPU resources and stalling indefinitely (minutes or more) while holding the main event loop. This means that process can't handle any more requests, leading to regular expression denial of service. This vulnerability has been patched in version 0.0.7.

Affected products

• Kludex python-multipart: before 0.0.7 — fixed in 0.0.7

How to fix

Upgrade to a fixed version: Kludex python-multipart 0.0.7. Check the vendor advisory for mitigations.

References

• https://github.com/Kludex/python-multipart/commit/20f0ef6b4e4caf7d69a667c54dff57fe467109a4
• https://github.com/Kludex/python-multipart/security/advisories/GHSA-2jv5-9r88-3w3p
• https://github.com/andrew-d/python-multipart/blob/d3d16dae4b061c34fe9d3c9081d9800c49fc1f7a/multipart/multipart.py#L72-L74
• https://github.com/encode/starlette/commit/13e5c26a27f4903924624736abd6131b2da80cc5
• https://github.com/encode/starlette/security/advisories/GHSA-93gm-qmq6-w238
• https://github.com/tiangolo/fastapi/commit/9d34ad0ee8a0dfbbcce06f76c2d5d851085024fc
• https://github.com/tiangolo/fastapi/releases/tag/0.109.1
• https://github.com/tiangolo/fastapi/security/advisories/GHSA-qf9m-vfgh-m389
• https://github.com/Kludex/python-multipart/commit/20f0ef6b4e4caf7d69a667c54dff57fe467109a4
• https://github.com/Kludex/python-multipart/security/advisories/GHSA-2jv5-9r88-3w3p
• https://github.com/andrew-d/python-multipart/blob/d3d16dae4b061c34fe9d3c9081d9800c49fc1f7a/multipart/multipart.py#L72-L74
• https://github.com/encode/starlette/commit/13e5c26a27f4903924624736abd6131b2da80cc5

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