CVE-2023-6134Network attack vector

Reflected XSS via wildcarded OIDC redirect

Published Dec 14, 2023 · Updated Feb 25, 2026

Reflected XSS in OIDC redirect validation in Red Hat Keycloak products allows remote authenticated users to run script via a crafted redirect_uri. RedirectUtils accepts a disallowed URI scheme when a wildcard is appended to a registered redirect, allowing the crafted value through validation. Exploitation requires low-privileged access and a user to follow the crafted authorization request; successful script execution can read or modify browser-accessible session data.

CVSS severity4.6
Medium
EPSS probability0.91%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in OIDC redirect validation in Red Hat Keycloak products allows remote authenticated users to run script via a crafted redirect_uri. RedirectUtils accepts a disallowed URI scheme when a wildcard is appended to a registered redirect, allowing the crafted value through validation. Exploitation requires low-privileged access and a user to follow the crafted authorization request; successful script execution can read or modify browser-accessible session data.

The record

CVE
CVE-2023-6134
Published
Dec 14, 2023
Updated
Feb 25, 2026
Vendor
Red Hat
Product
RHEL-8 based Middleware Containers
Classifications
CWE-75, CWE-79, T1204.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Red Hat · RHEL-8 based Middleware ContainersAffected versions are unavailable in this record.
389 Directory Server · Red Hat Single Sign-OnAffected versions are unavailable in this record.
Red Hat · Red Hat build of Keycloak 22Affected versions are unavailable in this record.

Published CVSS scores

5.4NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
4.6Red HatCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-75Failure to Sanitize Special Elements into a Different Plane (Special Element Injection)
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001Malicious Link

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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