CVE-2026-53538
Fixed in a distro release EPSS <1%CVSS 3.7
Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, QuerystringParser treated ; as a field separator in application/x-www-form-urlencoded bodies, in addition to &. The WHATWG URL standard, modern browsers, and Python's urllib.parse (since the CVE-2021-23336 fix) treat only & as a separator. This creates a parser differential: the same bytes are tokenized into different fields than a WHATWG compliant intermediary would produce, allowing an attacker to smuggle extra form fields past an upstream body inspecting component. This vulnerability is fixed in 0.0.30.
Products: Kludex python-multipart
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| PyPI | python-multipart | 0.0.30 |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Chainguard | airflow-2 | no fix |
| Chainguard | airflow-3 | 3.2.2-r7 |
| Chainguard | airflow-core-2 | no fix |
| Chainguard | airflow-core-3 | 3.2.2-r3 |
| Chainguard | airflow-postgres-fips-3 | 3.2.2-r1 |
| Chainguard | litellm | 1.89.0-r2 |
| Chainguard | tritonserver-backend-vllm-cuda-12.9 | 25.9.0_git20260617-r0 |
| Chainguard | wazuh-manager-framework | 4.14.5-r4 |
| Chainguard | wazuh-manager-framework-fips | 4.14.5-r4 |
| Debian 12 | python-multipart | no fix |
| Debian 13 | python-multipart | no fix |
| Debian 14 | python-multipart | 0.0.32-1 |
| SUSE Linux Enterprise Server 16.0 | python-python-multipart | 0.0.20-160000.5.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | python-python-multipart | 0.0.20-160000.5.1 |
| Ubuntu 25.10 | python-multipart | no fix |
| Ubuntu 26.04 LTS | python-multipart | no fix |
| Ubuntu 26.10 | python-multipart | no fix |
| Ubuntu Pro 22.04 LTS | python-multipart | no fix |
| Ubuntu Pro 24.04 LTS | python-multipart | no fix |
| Wolfi | airflow-3 | 3.2.2-r7 |
| openSUSE Leap 16.0 | python-python-multipart | 0.0.20-160000.5.1 |
| openSUSE Tumbleweed | python-python-multipart | 0.0.32-1.1 |