{"id":"AZL-6808","summary":"CVE-2021-28957 affecting package python-lxml for versions less than 4.8.0-1","details":"An XSS vulnerability was discovered in python-lxml's clean module versions before 4.6.3. When disabling the safe_attrs_only and forms arguments, the Cleaner class does not remove the formaction attribute allowing for JS to bypass the sanitizer. A remote attacker could exploit this flaw to run arbitrary JS code on users who interact with incorrectly sanitized HTML. This issue is patched in lxml 4.6.3.","modified":"2026-04-01T05:21:20.390226Z","published":"2021-03-21T05:15:13Z","upstream":["CVE-2021-28957"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-28957"}],"affected":[{"package":{"name":"python-lxml","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/python-lxml"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.8.0-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-6808.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"}]}