{"id":"CVE-2020-13940","aliases":["BIT-nifi-2020-13940","GHSA-q4xf-3pmq-3hw8"],"url":"https://o3.security/vulnerability/CVE-2020-13940","summary":"Improper Restriction of XML External Entity Reference in Apache NiFi","details":"In Apache NiFi 1.0.0 to 1.11.4, the notification service manager and various policy authorizer and user group provider objects allowed trusted administrators to inadvertently configure a potentially malicious XML file. The XML file has the ability to make external calls to services (via XXE).","published":"2020-10-01T20:15:13.097Z","modified":"2026-07-09T00:21:13.383294Z","cvss":{"score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N"},"epss":{"score":0.01911,"percentile":0.7795,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"org.apache.nifi:nifi","fixedVersion":"1.12.0-RC1"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://nifi.apache.org/security#CVE-2020-13940"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T00:21:13.383294Z"}}