Allocation of Resources Without Limits or Throttling in python-multipart - CVE-2026-42561
Published: April 30, 2026
Vulnerability identifier: #VU128479
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-42561
CWE-ID: CWE-770
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Marcelo Trylesinski
Affected software:
python-multipart
python-multipart
Detailed vulnerability description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to allocation of resources without limits or throttling in the HEADER_FIELD_START, HEADER_FIELD, HEADER_VALUE_START, HEADER_VALUE and HEADER_VALUE_ALMOST_DONE headers. A remote attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.
How to mitigate CVE-2026-42561
Install updates from vendor's website.