{"id":"CVE-2020-1758","aliases":["EUVD-2022-0953","GHSA-c597-f74m-jgc2","RHSA-2020:2106","RHSA-2020:2107","RHSA-2020:2108"],"status":"published","title":"Improper Certificate Validation and Improper Validation of Certificate with Host Mismatch in Keycloak","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.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00928,"percentile":0.6085,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-295","CWE-297"],"published":"2020-05-15T18:52:52Z","modified":"2026-10-24T10:30:55Z","fixes":[{"ecosystem":"Maven","package":"org.keycloak:keycloak-parent","fixed_in":["10.0.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Maven","package":"org.keycloak:keycloak-parent","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"10.0.0"}]}]},{"source":"osv","ecosystem":"Maven","package":"org.keycloak:keycloak-parent","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"10.0.0"}]}],"versions":["1.0-alpha-1","1.0-alpha-1-12062013","1.0-alpha-2","1.0-alpha-3","1.0-alpha-4","1.0-beta-1","1.0-beta-1-20150521","1.0-beta-1-20150523","1.0-beta-2","1.0-beta-3","1.0-beta-4","1.0-final","1.0-rc-1","1.0-rc-2","1.0.1.Final","1.0.2.Final","1.0.3.Final","1.0.4.Final","1.0.5.Final","1.1.0.Beta1","1.1.0.Beta2","1.1.0.Final","1.1.1.Final","1.2.0.Beta1","1.2.0.CR1","1.2.0.Final","1.3.0.Final","1.3.1.Final","1.4.0.Final","1.5.0-Final","1.5.0.Final","1.5.1.Final","1.6.0.Final","1.6.1.Final","1.7.0.CR1","1.7.0.Final","1.8.0.Alpha1","1.8.0.CR1","1.8.0.CR2","1.8.0.CR3","1.8.0.Final","1.8.1.Final","1.9.0.CR1","1.9.0.Final","1.9.1.Final","1.9.2.Final","1.9.3.Final","1.9.4.Final","1.9.5.Final","1.9.7.Final","1.9.8.Final","2.0.0.CR1","2.0.0.Final","2.1.0.CR1","2.1.0.Final","2.2.0.CR1","2.2.0.Final","2.2.1.Final","2.3.0.CR1","2.3.0.Final","2.4.0.CR1","2.4.0.Final","2.5.0.CR1","2.5.0.Final","2.5.1.Final","2.5.4.Final","2.5.5.Final","3.0.0.CR1","3.0.0.Final","3.1.0.CR1","3.1.0.Final","3.2.0.CR1","3.2.0.Final","3.2.1.Final","3.3.0.CR1","3.3.0.CR2","3.3.0.Final","3.4.0.CR1","3.4.0.Final","3.4.1.CR1","3.4.1.Final","3.4.2.Final","3.4.3.Final","4.0.0.Beta1","4.0.0.Beta2","4.0.0.Beta3","4.0.0.Final","4.1.0.Final","4.2.0.Final","4.2.1.Final","4.3.0.Final","4.4.0.Final","4.5.0.Final","4.6.0.Final","4.7.0.Final","4.8.0.Final","4.8.1.Final","4.8.2.Final","4.8.3.Final","5.0.0","6.0.0","6.0.1","7.0.0","7.0.1","8.0.0","8.0.1","8.0.2","9.0.0","9.0.2","9.0.3"]},{"source":"osv","ecosystem":"Red Hat:red_hat_single_sign_on:7::el6","package":"rh-sso7-keycloak","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:4.8.20-1.Final_redhat_00001.1.el6sso"}]}],"bundled":3},{"source":"osv","ecosystem":"Red Hat:red_hat_single_sign_on:7::el6","package":"rh-sso7-keycloak-server","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:4.8.20-1.Final_redhat_00001.1.el6sso"}]}],"bundled":3},{"source":"osv","ecosystem":"Red Hat:red_hat_single_sign_on:7::el7","package":"rh-sso7-keycloak","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:4.8.20-1.Final_redhat_00001.1.el7sso"}]}],"bundled":3},{"source":"osv","ecosystem":"Red Hat:red_hat_single_sign_on:7::el7","package":"rh-sso7-keycloak-server","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:4.8.20-1.Final_redhat_00001.1.el7sso"}]}],"bundled":3},{"source":"osv","ecosystem":"Red Hat:red_hat_single_sign_on:7::el8","package":"rh-sso7-keycloak","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:4.8.20-1.Final_redhat_00001.1.el8sso"}]}],"bundled":3},{"source":"osv","ecosystem":"Red Hat:red_hat_single_sign_on:7::el8","package":"rh-sso7-keycloak-server","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:4.8.20-1.Final_redhat_00001.1.el8sso"}]}],"bundled":3}],"products":[{"vendor":"keycloak","product":"keycloak"},{"vendor":"red hat","product":"keycloak"},{"vendor":"redhat","product":"keycloak"},{"vendor":"redhat","product":"openstack"}],"references":[{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1758","tags":["x_refsource_CONFIRM","x_transferred","Issue Tracking","Vendor Advisory","report","web"]},{"url":"https://issues.redhat.com/browse/KEYCLOAK-13285","tags":["x_refsource_MISC","x_transferred","Permissions Required","Vendor Advisory","report","web","article"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-1758","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-c597-f74m-jgc2"},{"url":"https://access.redhat.com/errata/RHSA-2020:2106","tags":["advisory"]},{"url":"https://access.redhat.com/security/updates/classification/#important","tags":["article"]},{"url":"https://access.redhat.com/documentation/en-us/red_hat_single_sign-on/7.3/","tags":["article"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=1796756","tags":["report"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=1800527","tags":["report"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=1812514","tags":["report"]},{"url":"https://issues.redhat.com/browse/KEYCLOAK-13797","tags":["article"]},{"url":"https://security.access.redhat.com/data/csaf/v2/advisories/2020/rhsa-2020_2106.json","tags":["advisory"]},{"url":"https://access.redhat.com/security/cve/CVE-2020-1718","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2020-1718","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-1718","tags":["advisory"]},{"url":"https://access.redhat.com/security/cve/CVE-2020-1724","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2020-1724","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-1724","tags":["advisory"]},{"url":"https://access.redhat.com/security/cve/CVE-2020-1758","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2020-1758","tags":["advisory"]},{"url":"https://access.redhat.com/errata/RHSA-2020:2107","tags":["advisory"]},{"url":"https://issues.redhat.com/browse/KEYCLOAK-13798","tags":["article"]},{"url":"https://security.access.redhat.com/data/csaf/v2/advisories/2020/rhsa-2020_2107.json","tags":["advisory"]},{"url":"https://access.redhat.com/errata/RHSA-2020:2108","tags":["advisory"]},{"url":"https://issues.redhat.com/browse/KEYCLOAK-13799","tags":["article"]},{"url":"https://security.access.redhat.com/data/csaf/v2/advisories/2020/rhsa-2020_2108.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2020-1758","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.","status":"published","published":"2020-05-15T18:52:52Z","modified":"2024-08-04T06:46:30.91Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-297"],"updated_at":"2026-11-02T14:35:56.213477Z"}],"euvd":[{"id":"EUVD-2022-0953","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.","status":"published","published":"2020-05-15T18:52:52Z","modified":"2024-08-04T06:46:30Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-03T03:08:11.523019Z"}],"ghsa":[{"id":"GHSA-c597-f74m-jgc2","title":"Improper Certificate Validation and Improper Validation of Certificate with Host Mismatch in Keycloak","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.","status":"published","published":"2022-02-09T00:56:26Z","modified":"2023-02-01T05:05:16Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-295","CWE-297"],"updated_at":"2026-11-02T14:36:33.613868Z"}],"nvd":[{"id":"CVE-2020-1758","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.","status":"published","published":"2020-05-15T19:15:12.43Z","modified":"2026-06-17T03:02:20.68Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:P/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-297","CWE-295"],"updated_at":"2026-11-02T14:06:00.784809Z"}],"osv":[{"id":"CVE-2020-1758","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.","status":"published","published":"2020-05-15T19:15:12.43Z","modified":"2026-10-24T10:30:55.724315209Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:44:15.212689Z"},{"id":"GHSA-c597-f74m-jgc2","title":"Improper Certificate Validation and Improper Validation of Certificate with Host Mismatch in Keycloak","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.","status":"published","published":"2022-02-09T00:56:26Z","modified":"2023-11-08T04:02:43.494034Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-295","CWE-297"],"updated_at":"2026-11-02T15:46:44.571161Z"},{"id":"RHSA-2020:2106","title":"Red Hat Security Advisory: Red Hat Single Sign-On 7.3.8 security update on RHEL 6","status":"published","published":"2024-09-13T18:09:17Z","modified":"2026-06-29T10:30:14Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:53:07.072948Z"},{"id":"RHSA-2020:2107","title":"Red Hat Security Advisory: Red Hat Single Sign-On 7.3.8 security update on RHEL 7","status":"published","published":"2024-09-13T18:09:24Z","modified":"2026-06-29T10:30:14Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:53:07.072948Z"},{"id":"RHSA-2020:2108","title":"Red Hat Security Advisory: Red Hat Single Sign-On 7.3.8 security update on RHEL 8","status":"published","published":"2024-09-13T18:09:33Z","modified":"2026-06-29T10:30:15Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:53:07.072948Z"}]}}
