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Loop with Unreachable Exit Condition ('Infinite Loop') The advisory has been revoked - it doesn't affect any version of package python-urllib3.src  (opens in a new tab)

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EPSS
0.86% (76th percentile)

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  • Snyk IDSNYK-RHEL10-PYTHONURLLIB3SRC-12596877
  • published10 Sept 2025
  • disclosed1 Jun 2021
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Introduced: 1 Jun 2021

CVE-2021-33503  (opens in a new tab)
CWE-835  (opens in a new tab)

Amendment

The Red Hat security team deemed this advisory irrelevant for RHEL:10.

NVD Description

Note: Versions mentioned in the description apply only to the upstream python-urllib3.src package and not the python-urllib3.src package as distributed by RHEL.

An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.

References