CVE-2026-44432

Aliases:GHSA-mf9v-mfxr-j63jPYSEC-2026-142
Advisory lineage Upstream: 0 Downstream: 22
Analyzed
Published: 13 May 2026, 15:17
Last modified:22 Jul 2026, 12:08

Vulnerability Summary

Overall Risk (default)
medium
36/100
CVSS Score
8.9 HIGH
v4.0 (cve.org)
EPSS Score
0.68% LOW
1% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

13 May 2026, 15:17
Published
Vulnerability first disclosed
22 Jul 2026, 12:08
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v4.0•HIGH•Score: 8.9CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
  • v4.0•HIGH•Score: 8.9CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.68%• Percentile: 48%

Techniques & Countermeasures

  • CWE-409•Improper Handling of Highly Compressed Data (Data Amplification)

    The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.

Affected Systems

  • PyPI•urllib3

    ≥ 2.6.0, < 2.7.0

  • python•urllib3

    ≥ 2.6.0, < 2.7.0

  • urllib3•urllib3

    ≥ 2.6.0, < 2.7.0

References (59)