Red Hat Keycloak Message error_description cross site scripting

Summaryinfo

A vulnerability was found in Red Hat Keycloak. It has been classified as problematic. This affects an unknown function of the component Message Handler. This manipulation of the argument error_description causes cross site scripting. This vulnerability is tracked as CVE-2025-10044. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability classified as problematic was found in Red Hat Keycloak (unknown version). Affected by this vulnerability is an unknown code block of the component Message Handler. The manipulation of the argument error_description with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. The summary by CVE is:

A flaw was found in Keycloak. Keycloak’s account console and other pages accept arbitrary text in the error_description query parameter. This text is directly rendered in error pages without validation or sanitization. While HTML encoding prevents XSS, an attacker can craft URLs with misleading messages (e.g., fake support phone numbers or URLs), which are displayed within the trusted Keycloak UI. This creates a phishing vector, potentially tricking users into contacting malicious actors.

The advisory is shared at access.redhat.com. This vulnerability is known as CVE-2025-10044 since 09/05/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/07/2025). MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 265769 (Keycloak < 26.2.9 Multiple Vulnerabilities (GHSA-wc64-wmfm-46vw)(GHSA-xmcw-mv9p-7pq2)), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Tenable (265769), EUVD (EUVD-2025-27029) and CERT Bund (WID-SEC-2025-1987). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Red Hat Enterprise Linux
• Open Source Keycloak

Productinfo

Vendor

• Red Hat

Name

• Keycloak

License

• open-source

Website

• Vendor: https://www.redhat.com/

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Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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