{"id":"CVE-2021-39156","aliases":["GHSA-hqxw-mm44-gc4r"],"url":"https://o3.security/vulnerability/CVE-2021-39156","summary":"Istio Fragments in Path May Lead to Authorization Policy Bypass","details":"Istio is an open source platform for providing a uniform way to integrate microservices, manage traffic flow across microservices, enforce policies and aggregate telemetry data. Istio 1.11.0, 1.10.3 and below, and 1.9.7 and below contain a remotely exploitable vulnerability where an HTTP request with `#fragment` in the path may bypass Istio’s URI path based authorization policies. Patches are available in Istio 1.11.1, Istio 1.10.4 and Istio 1.9.8. As a work around a Lua filter may be written to normalize the path.","published":"2021-08-24T23:15:10.413Z","modified":"2026-07-09T10:21:00.770562Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"istio.io/istio","fixedVersion":"1.9.8"},{"ecosystem":"Go","name":"istio.io/istio","fixedVersion":"1.10.4"},{"ecosystem":"Go","name":"istio.io/istio","fixedVersion":"1.11.1"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/istio/istio/security/advisories/GHSA-hqxw-mm44-gc4r"},{"type":"ADVISORY","url":"https://istio.io/latest/news/security/istio-security-2021-008"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T10:21:00.770562Z"}}