Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
Maven
Not in CISA KEV
MEDIUM severity

GHSA-9vm7-v8wj-3fqw keycloak-core

MEDIUM

GHSA-9vm7-v8wj-3fqw 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-core: open redirect via "form_post.jwt" JARM response mode

Also known asCVE-2023-6927
Published
Jan 23, 2024
Updated
Sep 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 18, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
1.1%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs64th percentile — riskier than 64% of all scored CVEsHighest risk

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

GHSA-9vm7-v8wj-3fqw 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

1 pkg affected
org.keycloak:keycloak-core

Real-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

An incomplete fix was found in Keycloak Core patch. An attacker can steal authorization codes or tokens from clients using a wildcard in the JARM response mode "form_post.jwt". It is observed that changing the response_mode parameter in the original proof of concept from "form_post" to "form_post.jwt" can bypass the security patch implemented to address CVE-2023-6134.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
Mavenorg.keycloak:keycloak-coreall versions23.0.4org.keycloak:keycloak-core:23.0.4

Detection & mitigation playbook

Open-source dependency
  1. Detect

    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.

  2. 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 GHSA-9vm7-v8wj-3fqw is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-9vm7-v8wj-3fqw can be triaged on real exposure rather than presence alone.

Tailored to GHSA-9vm7-v8wj-3fqw. 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 HatModerate

Red Hat rates this as a moderate, following the same case for CVE-2023-6134, but with another response mode with JSON Web Token.

ProductFixed inAdvisory
Red Hat build of Keycloak 22rhbk/keycloak-rhel9:22-7RHSA-2024:0100
Red Hat build of Keycloak 22.0.8keycloak-coreRHSA-2024:0101
Red Hat Single Sign-On 7rh-sso7-keycloakRHSA-2024:0804
Red Hat Single Sign-On 7.6 for RHEL 7rh-sso7-keycloak-0:18.0.11-3.redhat_00001.1.el7ssoRHSA-2024:0094
Red Hat Single Sign-On 7.6 for RHEL 7rh-sso7-keycloak-0:18.0.12-1.redhat_00001.1.el7ssoRHSA-2024:0798
Red Hat Single Sign-On 7.6 for RHEL 8rh-sso7-keycloak-0:18.0.11-3.redhat_00001.1.el8ssoRHSA-2024:0095
Red Hat Single Sign-On 7.6 for RHEL 8rh-sso7-keycloak-0:18.0.12-1.redhat_00001.1.el8ssoRHSA-2024:0799
Red Hat Single Sign-On 7.6 for RHEL 9rh-sso7-keycloak-0:18.0.11-3.redhat_00001.1.el9ssoRHSA-2024:0096

Frequently Asked Questions

An incomplete fix was found in Keycloak Core patch. An attacker can steal authorization codes or tokens from clients using a wildcard in the JARM response mode "form_post.jwt". It is observed that changing the response_mode parameter in the original proof of concept from "form_post" to "form_post.jwt" can bypass the security patch implemented to address CVE-2023-6134.
O3 Security · Impact-Aware SCA

Is GHSA-9vm7-v8wj-3fqw in your dependencies?

O3 Security finds GHSA-9vm7-v8wj-3fqw across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-9vm7-v8wj-3fqw: keycloak-core | O3 Security