CVE-2026-0871: A flaw was found in Keycloak

Q: How do I fix CVE-2026-0871?

build of keycloak: upgrade to 26.4.9; keycloak: upgrade to 26.4.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-0871 being exploited?

CVE-2026-0871 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-2026-0871 affect?

CVE-2026-0871 affects build of keycloak, keycloak. Severity is medium (CVSS 4.9). A flaw was found in Keycloak. An administrator with `manage-users` permission can bypass the "Only administrators can view" setting for unmanaged attributes, allowing them to modify these attributes. This improper access control can lead to

Q: How urgent is CVE-2026-0871?

Priority 29/100. On your watchlist

Routine

MEDIUM 4.9WATCHLISTUPGRADEUPGRADE

CVE-2026-0871 is a medium-severity flaw (CVSS 4.9) affecting build of keycloak, 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. An administrator with `manage-users` permission can bypass the "Only administrators can view" setting for unmanaged attributes, allowing them to modify these attributes. This improper access control can lead to unauthorized changes to user profiles, even when the system is configured to restrict such modifications.

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	0.3% (top 72%)
CISA exploited list	No
Weakness	CWE-266
Published	2026-02-27
Last modified	2026-06-17

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

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-02-27 08:17 UTCPublished CVE record published
2026-06-17 10:11 UTCUpdated Record last modified

redhat build of keycloak UPGRADE

Affected: < 26.4.9 · all versions

Fixed in: 26.4.9

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 26.4.9 (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.

redhat keycloak UPGRADE

Affected: < 26.4.0

Fixed in: 26.4.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 26.4.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade 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-2026-0871?

build of keycloak: upgrade to 26.4.9; keycloak: upgrade to 26.4.0. Exact commands for each OS are on this page.

Is CVE-2026-0871 being exploited?

CVE-2026-0871 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-2026-0871 affect?

CVE-2026-0871 affects build of keycloak, keycloak. Severity is medium (CVSS 4.9). A flaw was found in Keycloak. An administrator with `manage-users` permission can bypass the "Only administrators can view" setting for unmanaged attributes, allowing them to modify these attributes. This improper access control can lead to

How urgent is CVE-2026-0871?

Priority 29/100. On your watchlist

Software pages

Keycloak vulnerabilities

Related CVEs

CVE-2026-37982 MEDIUM 6.8 UPGRADE A flaw was found in Keycloak
CVE-2026-37979 MEDIUM 6.5 UPGRADE A flaw was found in Keycloak
CVE-2026-4634 HIGH 7.5 DOWNGRADE A flaw was found in Keycloak
CVE-2026-4636 HIGH 8.1 DOWNGRADE A flaw was found in Keycloak
CVE-2026-4282 HIGH 7.4 DOWNGRADE A flaw was found in Keycloak

References

← Back to latest CVEs