CVE-2023-6134: A flaw was found in Keycloak that prevents certain schemes in redirects, but permits them if a wildcard is app

This month

MEDIUM 4.6WATCHLISTUPGRADEUPGRADEDOWNGRADE

CVE-2023-6134 is a medium-severity flaw (CVSS 4.6) affecting single sign-on, keycloak, openshift container platform. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A flaw was found in Keycloak that prevents certain schemes in redirects, but permits them if a wildcard is appended to the token. This issue could allow an attacker to submit a specially crafted request leading to cross-site scripting (XSS) or further attacks. This flaw is the result of an incomplete fix for CVE-2020-10748.

Why this priority

Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	4.6 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	1.3% (top 29%)
CISA exploited list	No
Weakness	CWE-79
Published	2023-12-14
Last modified	2026-09-22

Publisher (CNA): Red Hat, Inc. · Vendor: redhat

Last updated 2026-09-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-12-14 22:15 UTCPublished CVE record published
2026-09-22 04:17 UTCUpdated Record last modified

redhat single sign-on UPGRADE

Affected: < 7.6 · all versions

Fixed in: 7.6

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy single-sign-on || rpm -q single-sign-on || single-sign-on --version

2. UPGRADE to 7.6 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade single-sign-on

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade single-sign-on

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

redhat keycloak UPGRADE

Affected: < 22.0.7

Fixed in: 22.0.7

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy keycloak || rpm -q keycloak || keycloak --version

2. UPGRADE to 22.0.7 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade keycloak

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade keycloak

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

redhat openshift container platform DOWNGRADE

Affected: 4.11 · 4.12

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.11

1. Check installed version

apt-cache policy openshift-container-platform || rpm -q openshift-container-platform || openshift-container-platform --version

2. No fixed release: DOWNGRADE to a release before 4.11 (Debian / Ubuntu)

apt-cache madison openshift-container-platform sudo apt install openshift-container-platform=<VERSION_BEFORE_4.11> sudo apt-mark hold openshift-container-platform

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list openshift-container-platform sudo dnf downgrade openshift-container-platform-<VERSION_BEFORE_4.11> sudo dnf versionlock add openshift-container-platform

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

redhat openshift container platform for power DOWNGRADE

Affected: 4.9 · 4.10

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.9

1. Check installed version

apt-cache policy openshift-container-platform-for-power || rpm -q openshift-container-platform-for-power || openshift-container-platform-for-power --version

2. No fixed release: DOWNGRADE to a release before 4.9 (Debian / Ubuntu)

apt-cache madison openshift-container-platform-for-power sudo apt install openshift-container-platform-for-power=<VERSION_BEFORE_4.9> sudo apt-mark hold openshift-container-platform-for-power

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list openshift-container-platform-for-power sudo dnf downgrade openshift-container-platform-for-power-<VERSION_BEFORE_4.9> sudo dnf versionlock add openshift-container-platform-for-power

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

redhat openshift container platform ibm z systems DOWNGRADE

Affected: 4.9 · 4.10

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.9

1. Check installed version

apt-cache policy openshift-container-platform-ibm-z-systems || rpm -q openshift-container-platform-ibm-z-systems || openshift-container-platform-ibm-z-systems --version

2. No fixed release: DOWNGRADE to a release before 4.9 (Debian / Ubuntu)

apt-cache madison openshift-container-platform-ibm-z-systems sudo apt install openshift-container-platform-ibm-z-systems=<VERSION_BEFORE_4.9> sudo apt-mark hold openshift-container-platform-ibm-z-systems

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list openshift-container-platform-ibm-z-systems sudo dnf downgrade openshift-container-platform-ibm-z-systems-<VERSION_BEFORE_4.9> sudo dnf versionlock add openshift-container-platform-ibm-z-systems

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-6134?

single sign-on: upgrade to 7.6; keycloak: upgrade to 22.0.7; openshift container platform: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-6134 being exploited?

CVE-2023-6134 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-6134 affect?

CVE-2023-6134 affects single sign-on, keycloak, openshift container platform. Severity is medium (CVSS 4.6). A flaw was found in Keycloak that prevents certain schemes in redirects, but permits them if a wildcard is appended to the token. This issue could allow an attacker to submit a specially crafted request leading to cross-site scripting (XSS)

How urgent is CVE-2023-6134?

Priority 44/100. Public exploit reference; On your watchlist

Software pages

Keycloak vulnerabilities · Red Hat OpenShift vulnerabilities

Related CVEs

CVE-2019-10219 MEDIUM 6.1 UPGRADE DOWNGRADE A vulnerability was found in Hibernate-Validator
CVE-2023-6927 MEDIUM 4.6 MITIGATE DOWNGRADE A flaw was found in Keycloak
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CVE-2023-6291 HIGH 7.1 UPGRADE DOWNGRADE A flaw was found in the redirect_uri validation logic in Keycloak
CVE-2026-16093 MEDIUM 5.4 MITIGATE DOWNGRADE Keycloak provides a mechanism called Client Policies to enforce security requirements on clients, such as requ

References

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