How severe is CVE-2026-37978?

CVE-2026-37978 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-37978 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-37978?

CVE-2026-37978 affects Redhat Build Of Keycloak. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-37978?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-37978 have an EU (EUVD) identifier?

Yes. CVE-2026-37978 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30882.

When was CVE-2026-37978 published?

CVE-2026-37978 was published on 2026-05-19 and last updated on 2026-06-17.

CVE-2026-37978

CVE-2026-37978 is a medium-severity vulnerability in Redhat Build Of Keycloak with a CVSS 3.x base score of 4.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-639.

Key facts

Severity: Medium (CVSS 3.x base score 4.9)
EPSS exploit prediction: 0% (32nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-30882
Weakness: CWE-639
Affected product: Redhat Build Of Keycloak
Published: 2026-05-19
Last modified: 2026-06-17

Description

A flaw was found in Keycloak. A low-privilege administrator with the 'view-clients' role can exploit this by invoking the 'evaluate-scopes' Admin API endpoints with an arbitrary user ID (userId) parameter. This vulnerability allows for cross-role personally identifiable information (PII) leakage, enabling unauthorized visibility into user identities and authorizations across the realm. Exploitation is possible remotely via network access to the Admin API.

Frequently asked questions

What is CVE-2026-37978?: A flaw was found in Keycloak. A low-privilege administrator with the 'view-clients' role can exploit this by invoking the 'evaluate-scopes' Admin API endpoints with an arbitrary user ID (userId) parameter. This vulnerability allows for cross-role personally identifiable information (PII) leakage, enabling unauthorized visibility into user identities and authorizations across the realm. Exploitation is possible remotely via network access to the Admin API.
How severe is CVE-2026-37978?: CVE-2026-37978 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-37978 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-37978?: CVE-2026-37978 affects Redhat Build Of Keycloak. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-37978?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-37978 have an EU (EUVD) identifier?: Yes. CVE-2026-37978 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30882.
When was CVE-2026-37978 published?: CVE-2026-37978 was published on 2026-05-19 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:*

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