USN-8343-1: multipart vulnerability

Publication date

28 May 2026

Overview

multipart could be made to use excessive resources if it received specially crafted input.


Packages

  • multipart - library for handling multipart/form-data POST requests

Details

It was discovered that multipart had an ambiguous regular expression
alternation when handling certain HTTP header values. A remote attacker
could possibly use this issue to cause multipart to use excessive
resources, leading to a denial of service.

It was discovered that multipart had an ambiguous regular expression
alternation when handling certain HTTP header values. A remote attacker
could possibly use this issue to cause multipart to use excessive
resources, leading to a denial of service.

Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
26.04 LTS resolute python3-multipart –  1.3.0-3ubuntu0.1
25.10 questing python3-multipart –  1.2.1-2+deb13u1build0.25.10.1

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