CVE-2026-44432

urllib3 is an HTTP client library for Python. From 2.6.0 to before 2.7.0, urllib3 could decompress the whole response instead of the requested portion (1) during the second HTTPResponse.read(amt=N) call when the response was decompressed using the official Brotli library or (2) when HTTPResponse.drain_conn() was called after the response had been read and decompressed partially (compression algorithm did not matter here). These issues could cause urllib3 to fully decode a small amount of highly compressed data in a single operation. This could result in excessive resource consumption (high CPU usage and massive memory allocation for the decompressed data) on the client side. This vulnerability is fixed in 2.7.0.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/urllib3/urllib3/security/advisories/GHSA-mf9v-mfxr-j63j	Mitigation Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:*

History

14 May 2026, 13:49

Type	Values Removed	Values Added
CPE		cpe:2.3:a:python:urllib3::::::::
References	~~() https://github.com/urllib3/urllib3/security/advisories/GHSA-mf9v-mfxr-j63j -~~	() https://github.com/urllib3/urllib3/security/advisories/GHSA-mf9v-mfxr-j63j - Mitigation, Vendor Advisory
First Time		Python Python urllib3
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 7.5

13 May 2026, 17:06

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-05-13 16:16

Updated : 2026-05-14 13:49

NVD link : CVE-2026-44432

Mitre link : CVE-2026-44432

CVE.ORG link : CVE-2026-44432

JSON object : View

Products Affected

python

urllib3

CWE

CWE-409

Improper Handling of Highly Compressed Data (Data Amplification)

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