DEBIAN-CVE-2021-33503

DEBIAN-CVE-2021-33503 PUBLISHED CVSS 7.5 HIGH

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.

Risk Scores

CVSS 3.1

7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Products

Vendor	Product	Versions
Debian:13	python-urllib3	0, 0, 0
Debian:11	python-urllib3	0, 0, 0
Debian:14	python-urllib3	0, 0, 0
Debian:12	python-urllib3	0, 0, 0

Timeline

Jun 29, 2021 CVE Published
Apr 28, 2026 CVE Updated

References

https://security-tracker.debian.org/tracker/CVE-2021-33503 advisory

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