How severe is CVE-2020-27826?

CVE-2020-27826 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-27826 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-27826?

CVE-2020-27826 primarily affects Redhat Keycloak. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-27826?

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

When was CVE-2020-27826 published?

CVE-2020-27826 was published on 2021-05-28 and last updated on 2026-06-17.

CVE-2020-27826

CVE-2020-27826 is a medium-severity vulnerability in Redhat Keycloak with a CVSS 3.x base score of 4.2. 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-250.

Key facts

Severity: Medium (CVSS 3.x base score 4.2)
CVSS v2: 4.9
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-250
Affected product: Redhat Keycloak
Published: 2021-05-28
Last modified: 2026-06-17

Description

A flaw was found in Keycloak before version 12.0.0 where it is possible to update the user's metadata attributes using Account REST API. This flaw allows an attacker to change its own NameID attribute to impersonate the admin user for any particular application.

Frequently asked questions

What is CVE-2020-27826?: A flaw was found in Keycloak before version 12.0.0 where it is possible to update the user's metadata attributes using Account REST API. This flaw allows an attacker to change its own NameID attribute to impersonate the admin user for any particular application.
How severe is CVE-2020-27826?: CVE-2020-27826 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-27826 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-27826?: CVE-2020-27826 primarily affects Redhat Keycloak. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-27826?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-27826 published?: CVE-2020-27826 was published on 2021-05-28 and last updated on 2026-06-17.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1905089

Affected products (4)

cpe:2.3:a:redhat:keycloak:*:*:*:*:*:*:*:*
cpe:2.3:a:redhat:single_sign-on:-:*:*:*:text-only:*:*:*
cpe:2.3:a:redhat:single_sign-on:7.4:*:*:*:*:*:*:*
cpe:2.3:a:redhat:single_sign-on:7.4.4:*:*:*:*:*:*:*

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