{"id":"ALPINE-CVE-2021-28363","details":"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.","modified":"2026-09-15T08:17:46.636249515Z","published":"2021-03-15T18:15:19.017Z","upstream":["CVE-2021-28363"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2021-28363"}],"affected":[{"package":{"name":"py3-urllib3","ecosystem":"Alpine:v3.14","purl":"pkg:apk/alpine/py3-urllib3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.26.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-28363.json"}},{"package":{"name":"py3-urllib3","ecosystem":"Alpine:v3.15","purl":"pkg:apk/alpine/py3-urllib3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.26.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-28363.json"}},{"package":{"name":"py3-urllib3","ecosystem":"Alpine:v3.16","purl":"pkg:apk/alpine/py3-urllib3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.26.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-28363.json"}},{"package":{"name":"py3-urllib3","ecosystem":"Alpine:v3.17","purl":"pkg:apk/alpine/py3-urllib3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.26.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-28363.json"}},{"package":{"name":"py3-urllib3","ecosystem":"Alpine:v3.18","purl":"pkg:apk/alpine/py3-urllib3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.26.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-28363.json"}},{"package":{"name":"py3-urllib3","ecosystem":"Alpine:v3.19","purl":"pkg:apk/alpine/py3-urllib3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.26.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-28363.json"}},{"package":{"name":"py3-urllib3","ecosystem":"Alpine:v3.20","purl":"pkg:apk/alpine/py3-urllib3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.26.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-28363.json"}},{"package":{"name":"py3-urllib3","ecosystem":"Alpine:v3.21","purl":"pkg:apk/alpine/py3-urllib3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.26.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-28363.json"}},{"package":{"name":"py3-urllib3","ecosystem":"Alpine:v3.22","purl":"pkg:apk/alpine/py3-urllib3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.26.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-28363.json"}},{"package":{"name":"py3-urllib3","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/py3-urllib3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.26.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-28363.json"}},{"package":{"name":"py3-urllib3","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/py3-urllib3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.26.4-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-28363.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"}]}