Red Hat Keycloak Single Sign-On keycloak-services information disclosure

Summaryinfo

A vulnerability described as problematic has been identified in Red Hat Keycloak Single Sign-On. Affected is an unknown function of the component keycloak-services. The manipulation results in information disclosure. This vulnerability is known as CVE-2026-107121. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Red Hat Keycloak Single Sign-On (unknown version). Affected is an unknown code block of the component keycloak-services. The manipulation with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. CVE summarizes:

A flaw was found in the SMTP email configuration handling of the keycloak-services component. When the STARTTLS option is enabled, Keycloak fails to strictly enforce an encrypted connection, allowing it to fall back to unencrypted communication if the encryption request is tampered with. An attacker who can intercept network traffic can exploit this to capture sensitive email credentials and message content in plain text.

The advisory is available at access.redhat.com. This vulnerability is traded as CVE-2026-107121 since 10/07/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 10/07/2026). This vulnerability is assigned to T1592 by the MITRE ATT&CK project.

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

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• Red Hat

Name

• Keycloak Single Sign-On

License

• open-source

Website

• Vendor: https://www.redhat.com/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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