{"id":"AZL-6821","summary":"CVE-2021-33503 affecting package python-urllib3 for versions less than 1.25.9-3","details":"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.","modified":"2026-04-01T05:21:22.302243Z","published":"2021-06-29T11:15:07Z","upstream":["CVE-2021-33503"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-33503"}],"affected":[{"package":{"name":"python-urllib3","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/python-urllib3"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.25.9-3"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-6821.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}