What’s Vulnerable › Vulnerabilities

CVE-2026-105302: Keycloak-services: keycloak-services: user session note mapper exposes upstream idp access tokens

• Severity: medium (CVSS 5.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-05 · updated 2026-10-06
• Weakness: CWE-200

Description

A flaw was found in the User Session Note mapper of the Keycloak identity and access management solution. The issue occurs because the mapper does not validate whether a requested session note contains sensitive internal credentials, such as federated access tokens from external identity providers. This allows a delegated client administrator to leak a user's upstream bearer tokens into the tokens issued to their managed application, potentially leading to unauthorized access to the user's data on external platforms.

Affected products

• Red Hat build of Keycloak 26.4: all versions

References

• https://access.redhat.com/security/cve/CVE-2026-105302
• https://bugzilla.redhat.com/show_bug.cgi?id=2545800

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