{"cve":"CVE-2020-1758","nvd":{"published":"2020-05-15T19:15:12.430","modified":"2026-06-17T03:02:20.680","status":"Modified","description":"A flaw was found in Keycloak in versions before 10.0.0, where it does not perform the TLS hostname verification while sending emails using the SMTP server. This flaw allows an attacker to perform a man-in-the-middle (MITM) attack.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","score":5.9},"cwes":["CWE-295","CWE-297"],"references":["https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1758","https://issues.redhat.com/browse/KEYCLOAK-13285","https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1758","https://issues.redhat.com/browse/KEYCLOAK-13285"],"products":["redhat:keycloak","redhat:openstack"],"source":"nvd","synced_at":"2026-10-19T21:04:18.695612450+00:00"},"epss":{"cve":"CVE-2020-1758","score":0.00928,"percentile":0.60557,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-c597-f74m-jgc2","url":"https://osv.dev/vulnerability/GHSA-c597-f74m-jgc2","summary":"Improper Certificate Validation and Improper Validation of Certificate with Host Mismatch in Keycloak","modified":"2023-11-08T04:02:43.494034Z","packages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-parent","purl":"pkg:maven/org.keycloak/keycloak-parent","ranges":["<10.0.0"],"fixed":["10.0.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}