Description
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.
Published: 2026-05-13
Score: 8.9 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-mf9v-mfxr-j63j urllib3: Decompression-bomb safeguards bypassed in parts of the streaming API
History

Fri, 15 May 2026 19:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 14 May 2026 14:00:00 +0000

Type Values Removed Values Added
First Time appeared Python
Python urllib3
CPEs cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:*
Vendors & Products Python
Python urllib3
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Wed, 13 May 2026 19:00:00 +0000

Type Values Removed Values Added
First Time appeared Urllib3
Urllib3 urllib3
Vendors & Products Urllib3
Urllib3 urllib3

Wed, 13 May 2026 16:15:00 +0000

Type Values Removed Values Added
Description 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.
Title urllib3: Decompression-bomb safeguards bypassed in parts of the streaming API
Weaknesses CWE-409
References
Metrics cvssV4_0

{'score': 8.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-15T18:25:06.331Z

Reserved: 2026-05-06T14:40:00.954Z

Link: CVE-2026-44432

cve-icon Vulnrichment

Updated: 2026-05-15T18:25:01.877Z

cve-icon NVD

Status : Analyzed

Published: 2026-05-13T16:16:57.303

Modified: 2026-05-14T13:49:25.483

Link: CVE-2026-44432

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-13T18:45:36Z

Weaknesses