DEBIAN-CVE-2021-28363

DEBIAN-CVE-2021-28363 PUBLISHED CVSS 6.5 MEDIUM

The urllib3 library 1.26.x before 1.26.4 for Python omits SSL certificate validation in some cases involving HTTPS to HTTPS proxies. The initial connection to the HTTPS proxy (if an SSLContext isn't given via proxy_config) doesn't verify the hostname of the certificate. This means certificates for different servers that still validate properly with the default urllib3 SSLContext will be silently accepted.

Risk Scores

CVSS 3.1

6.5

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

Affected Products

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

Timeline

Mar 15, 2021 CVE Published
Apr 28, 2026 CVE Updated

References

https://security-tracker.debian.org/tracker/CVE-2021-28363 advisory

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