CVE-2026-37978: A flaw was found in Keycloak

Q: How do I fix CVE-2026-37978?

build of keycloak: upgrade to 26.4.12. Exact commands for each OS are on this page.

Q: Is CVE-2026-37978 being exploited?

CVE-2026-37978 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-37978 affect?

CVE-2026-37978 affects build of keycloak. Severity is medium (CVSS 4.9). 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 cros

Q: How urgent is CVE-2026-37978?

Priority 31/100. On your watchlist

Routine

MEDIUM 4.9WATCHLISTUPGRADE

CVE-2026-37978 is a medium-severity flaw (CVSS 4.9) affecting build of keycloak. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 A

Why this priority

On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	4.9 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	0.4% (top 63%)
CISA exploited list	No
Weakness	CWE-639
Published	2026-05-19
Last modified	2026-10-25

Publisher (CNA): Red Hat, Inc. · Vendor: redhat

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-19 12:16 UTCPublished CVE record published
2026-10-25 23:10 UTCUpdated Record last modified

redhat build of keycloak UPGRADE

Affected: < 26.4.12

Fixed in: 26.4.12

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy build-of-keycloak || rpm -q build-of-keycloak || build-of-keycloak --version

2. UPGRADE to 26.4.12 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade build-of-keycloak

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade build-of-keycloak

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-37978?

build of keycloak: upgrade to 26.4.12. Exact commands for each OS are on this page.

Is CVE-2026-37978 being exploited?

CVE-2026-37978 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-37978 affect?

CVE-2026-37978 affects build of keycloak. Severity is medium (CVSS 4.9). 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 cros

How urgent is CVE-2026-37978?

Priority 31/100. On your watchlist

Software pages

Keycloak vulnerabilities

Related CVEs

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CVE-2026-4633 LOW 3.7 MITIGATE A flaw was found in Keycloak
CVE-2026-4628 MEDIUM 4.3 MITIGATE A flaw was found in Keycloak

References

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