How severe is CVE-2026-9801?

CVE-2026-9801 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 none, integrity none, and availability high.

Is CVE-2026-9801 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-9801?

CVE-2026-9801 affects Redhat Build Of Keycloak. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-9801?

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

Does CVE-2026-9801 have an EU (EUVD) identifier?

Yes. CVE-2026-9801 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32718.

When was CVE-2026-9801 published?

CVE-2026-9801 was published on 2026-05-28 and last updated on 2026-06-26.

CVE-2026-9801

CVE-2026-9801 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-1284.

Key facts

Severity: Medium (CVSS 3.x base score 4.9)
EPSS exploit prediction: 0% (38th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-32718
Weakness: CWE-1284
Affected product: Redhat Build Of Keycloak
Published: 2026-05-28
Last modified: 2026-06-26

Description

A flaw was found in Keycloak. A remote attacker with high privileges, such as a realm administrator configuring a malicious Lightweight Directory Access Protocol (LDAP) server or an attacker compromising an upstream LDAP server, could exploit this vulnerability. By sending a malformed LDAP password policy response during a password authentication request, the attacker can trigger an OutOfMemoryError. This causes the Keycloak Java Virtual Machine (JVM) to terminate, leading to a denial of service (DoS) for all realms on the affected node.

Frequently asked questions

What is CVE-2026-9801?: A flaw was found in Keycloak. A remote attacker with high privileges, such as a realm administrator configuring a malicious Lightweight Directory Access Protocol (LDAP) server or an attacker compromising an upstream LDAP server, could exploit this vulnerability. By sending a malformed LDAP password policy response during a password authentication request, the attacker can trigger an OutOfMemoryError. This causes the Keycloak Java Virtual Machine (JVM) to terminate, leading to a denial of service (DoS) for all realms on the affected node.
How severe is CVE-2026-9801?: CVE-2026-9801 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 none, integrity none, and availability high.
Is CVE-2026-9801 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-9801?: CVE-2026-9801 affects Redhat Build Of Keycloak. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-9801?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-9801 have an EU (EUVD) identifier?: Yes. CVE-2026-9801 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32718.
When was CVE-2026-9801 published?: CVE-2026-9801 was published on 2026-05-28 and last updated on 2026-06-26.

References

Affected products (1)

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

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