Allocation of Resources Without Limits or Throttling Affecting python-urllib3 package, versions <0:1.25.9-1.amzn2.0.11


Severity

Recommended
0.0
high
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.34% (26th percentile)

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  • Snyk IDSNYK-AMZN2-PYTHONURLLIB3-20847410
  • published13 Oct 2026
  • disclosed29 Sept 2026

Introduced: 29 Sep 2026

NewCVE-2026-97689  (opens in a new tab)
CWE-770  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2 python-urllib3 to version 0:1.25.9-1.amzn2.0.11 or higher.
This issue was patched in ALAS2-2026-3973.

NVD Description

Note: Versions mentioned in the description apply only to the upstream python-urllib3 package and not the python-urllib3 package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2 relevant fixed versions and status.

urllib3 is an HTTP client library for Python. From 1.10.3 until 2.8.0, the HTTPResponse.read_chunked and HTTPResponse.stream methods can allocate unbounded memory because the streaming chunk parser buffers the chunk-size field until newline or EOF without a length bound. The trigger is that a malicious server returns Transfer-Encoding: chunked followed by a very long run of bytes without a newline. The attack mechanism is that a malicious HTTP server sends a very long unterminated chunk-size line. The impact is that unbounded memory allocation can exhaust the client process. This issue is fixed in version 2.8.0.

CVSS Base Scores

version 3.1