CVE-2023-6927 — keycloak-core
MEDIUMCVE-2023-6927 is a medium-severity (CVSS 4.6) Open Redirect vulnerability in org.keycloak:keycloak-core. A fix is available for org.keycloak:keycloak-core — see the affected versions and patch details below.
Keycloak: open redirect via "form_post.jwt" jarm response mode
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-6927 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.keycloak:keycloak-coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
A flaw was found in Keycloak. This issue may allow an attacker to steal authorization codes or tokens from clients using a wildcard in the JARM response mode "form_post.jwt" which could be used to bypass the security patch implemented to address CVE-2023-6134.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.keycloak:keycloak-core | all versions | 23.0.4org.keycloak:keycloak-core:23.0.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.keycloak:keycloak-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.keycloak:keycloak-core to 23.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-6927 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-6927 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-6927. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat rates this as a moderate, following the same case for CVE-2023-6134, but with another response mode with JSON Web Token.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat build of Keycloak 22 | rhbk/keycloak-rhel9:22-7 | RHSA-2024:0100 |
| Red Hat build of Keycloak 22.0.8 | keycloak-core | RHSA-2024:0101 |
| Red Hat Single Sign-On 7 | rh-sso7-keycloak | RHSA-2024:0804 |
| Red Hat Single Sign-On 7.6 for RHEL 7 | rh-sso7-keycloak-0:18.0.11-3.redhat_00001.1.el7sso | RHSA-2024:0094 |
| Red Hat Single Sign-On 7.6 for RHEL 7 | rh-sso7-keycloak-0:18.0.12-1.redhat_00001.1.el7sso | RHSA-2024:0798 |
| Red Hat Single Sign-On 7.6 for RHEL 8 | rh-sso7-keycloak-0:18.0.11-3.redhat_00001.1.el8sso | RHSA-2024:0095 |
| Red Hat Single Sign-On 7.6 for RHEL 8 | rh-sso7-keycloak-0:18.0.12-1.redhat_00001.1.el8sso | RHSA-2024:0799 |
| Red Hat Single Sign-On 7.6 for RHEL 9 | rh-sso7-keycloak-0:18.0.11-3.redhat_00001.1.el9sso | RHSA-2024:0096 |
Frequently Asked Questions
Is CVE-2023-6927 in your dependencies?
O3 Security finds CVE-2023-6927 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.