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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | keycloak | keycloak versions before 10.0.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Single Sign On 7 | rh-sso7-keycloak +1 | 4.8.20-1.Final_redhat_00001.1.el6sso | RHSA-2020:2108, RHSA-2020:2107, RHSA-2020:2106 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.keycloak:keycloak-parent | < 10.0.0 | 10.0.0 | GHSA-c597-f74m-jgc2 |
Advisories 3
- RHSA-2020:2108 Red Hat Security Advisory: Red Hat Single Sign-On 7.3.8 security update on RHEL 8 Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2020:2106 Red Hat Security Advisory: Red Hat Single Sign-On 7.3.8 security update on RHEL 6 Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2020:2107 Red Hat Security Advisory: Red Hat Single Sign-On 7.3.8 security update on RHEL 7 Red Hat Security Advisories (RHSA) · Jun 29, 2026