CVE•Published 2026-05-28•Modified 2026-06-03•0 articles on news•5 live references•NVD data

CVE-2026-9801Redhat · Build_of_keycloak

Vulnerability data via NVD (ingested)

CVSS v3.1

4.9

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

EPSS percentile

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Weaknesses (CWE)

CWE-1284Improper Validation of Specified Quantity in Input

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.

Timeline

Published 2026-05-28

Modified 2026-06-03

External references

NVD MITRE Exploit-DB Sploitus VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-9801

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Redhat Build Of Keycloak"

All exposed Redhat Build Of Keycloak instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Build Of Keycloak"

HTTP body or banner mentions "Build Of Keycloak" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-9801