{"id":"CVE-2021-31920","details":"Istio before 1.8.6 and 1.9.x before 1.9.5 has a remotely exploitable vulnerability where an HTTP request path with multiple slashes or escaped slash characters (%2F or %5C) could potentially bypass an Istio authorization policy when path based authorization rules are used.","modified":"2026-07-08T21:26:50.894501Z","published":"2021-05-27T05:15:06.880Z","references":[{"type":"EVIDENCE","url":"https://istio.io/latest/news/security/istio-security-2021-005/"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/istio/istio","events":[{"introduced":"0"},{"fixed":"1aa9fc7a594d6ffc88ff8fd6cd416d8bafe4b214"},{"introduced":"b63e1966c245924b10a0915a671a656540ed7a45"},{"fixed":"67362755b7ca63ff1442d627a733627ed5c75df4"}],"database_specific":{"cpe":"cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"1.8.6"},{"introduced":"1.9.0"},{"fixed":"1.9.5"}],"source":"CPE_RANGE"}}],"versions":["1.9.4","1.9.2","1.8.4","1.9.1","1.8.3","1.9.0","1.8.2","1.8.1","1.8.0-rc.1","1.8.0","1.8.0-rc.0","1.8.0-alpha.2","1.8.0-alpha.0","1.7.0-alpha.0","1.6.0-alpha.2","1.6.0-alpha.1","1.6.0-alpha.0","1.5.0-beta.2","1.5.0-beta.1","1.5.0-alpha.0","1.2.0-rc.3","1.2.0-rc.0","1.1.0-snapshot.2","1.1.0.snapshot.1","1.1.0.snapshot.0","1.0.0-snapshot.0","0.6.0","0.5.0","0.3.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-31920.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"}]}