Description
Red Hat Keycloak before version 2.5.1 has an implementation of HMAC verification for JWS tokens that uses a method that runs in non-constant time, potentially leaving the application vulnerable to timing attacks.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | keycloak | 2.5.1 | — |
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 +1 | 1-2.jbcs.el6 | RHSA-2017:0873, RHSA-2017:0872 |
| Red Hat Single Sign On 7 | rh-sso7-freemarker | 2.3.23-1.redhat_2.2.jbcs.el6 | RHSA-2017:0873, RHSA-2017:0872 |
| Red Hat Single Sign On 7 | rh-sso7-javapackages-tools +1 | 3.4.1-5.15.3.jbcs.el6 | RHSA-2017:0873, RHSA-2017:0872 |
| Red Hat Single Sign On 7 | rh-sso7-keycloak +1 | 2.5.5-2.Final_redhat_1.1.jbcs.el6 | RHSA-2017:0873, RHSA-2017:0872 |
| Red Hat Single Sign On 7 | rh-sso7-libunix-dbus-java +1 | 0.8.0-2.jbcs.el6 | RHSA-2017:0873, RHSA-2017:0872 |
| Red Hat Single Sign On 7 | rh-sso7-liquibase +1 | 3.4.1-2.redhat_2.1.jbcs.el6 | RHSA-2017:0873, RHSA-2017:0872 |
| Red Hat Single Sign On 7 | rh-sso7-twitter4j +1 | 4.0.4-1.redhat_3.1.jbcs.el6 | RHSA-2017:0873, RHSA-2017:0872 |
| Red Hat Single Sign On 7 | rh-sso7-zxing +2 | 3.2.1-1.redhat_4.1.jbcs.el6 | RHSA-2017:0873, RHSA-2017:0872 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.keycloak:keycloak-core | < 2.5.1 | 2.5.1 | GHSA-w6gv-3r3v-gwgj |
Advisories 2
- RHSA-2017:0873 Red Hat Security Advisory: Red Hat Single Sign-On 7.1 update on RHEL 7 Red Hat Security Advisories (RHSA) · Mar 18, 2026
- RHSA-2017:0872 Red Hat Security Advisory: Red Hat Single Sign-On 7.1 update on RHEL 6 Red Hat Security Advisories (RHSA) · Mar 18, 2026
References
- RHSA-2017:0876 vendor-advisory
- 1038180 vdb-entry
- https://bugzilla.redhat.com/show_bug.cgi?id=1412376
- 97393 vdb-entry
- RHSA-2017:0873 vendor-advisory
- RHSA-2017:0872 vendor-advisory