cvedb.io
CVE-2021-33503
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2021-06-29T11:15:07.847 · Last modified 2026-06-17T03:54:41.387

Summary

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.

Affected products

python — urllib3

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.