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

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

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.

Source published

5 Oct 2026 05:51:58 UTC

Source modified

5 Oct 2026 14:55:01 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

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CVSS 3.1 · 5.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N