REDHAT-BUG-2419467: High severity pypi/urllib3 vulnerability

Published Dec 5, 2025
·
Updated

urllib3 is a user-friendly HTTP client library for Python. Starting in version 1.0 and prior to 2.6.0, the Streaming API improperly handles highly compressed data. urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading the content in chunks, rather than loading the entire response body into memory at once. When streaming a compressed response, urllib3 can perform decoding or decompression based on the HTTP Content-Encoding header (e.g., gzip, deflate, br, or zstd). The library must read compressed data from the network and decompress it until the requested chunk size is met. Any resulting decompressed data that exceeds the requested amount is held in an internal buffer for the next read operation. The decompression logic could cause urllib3 to fully decode a small amount of highly compressed data in a single operation. This can result in excessive resource consumption (high CPU usage and massive memory allocation for the decompressed data.

Affected Software

1 affected component
pypi/urllib3>=1.0<2.6.0

Event History

Dec 5, 2025
Data Sourced
via Red Hat·05:02 PM
DescriptionSeverityAffected Software

Frequently Asked Questions

1

What is the severity of REDHAT-BUG-2419467?

The severity of REDHAT-BUG-2419467 is considered high due to the potential for denial of service when handling highly compressed data.

2

How do I fix REDHAT-BUG-2419467?

To fix REDHAT-BUG-2419467, upgrade urllib3 to a version greater than 2.6.0.

3

What versions of urllib3 are affected by REDHAT-BUG-2419467?

The affected versions are urllib3 from 1.0 to 2.6.0.

4

What is the impact of the vulnerability identified in REDHAT-BUG-2419467?

The impact of REDHAT-BUG-2419467 is that it may lead to application crashes or performance degradation when processing highly compressed data.

5

Is there a known exploit for REDHAT-BUG-2419467?

As of now, there is no known public exploit for REDHAT-BUG-2419467, but it is recommended to address it promptly.

Contact

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