FKIE_CVE-2026-9801

Vulnerability from fkie_nvd - Published: 2026-05-28 06:16 - Updated: 2026-06-03 19:38
Severity
4.9 (Medium) - CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Summary
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.
References
secalert@redhat.comhttps://access.redhat.com/security/cve/CVE-2026-9801Vendor Advisory, Mitigation
secalert@redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=2482473Issue Tracking, Vendor Advisory
Impacted products
Vendor Product Version
redhat build_of_keycloak -
To clipboard 

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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "id": "CVE-2026-9801",
  "lastModified": "2026-06-03T19:38:35.473",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 4.9,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "HIGH",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
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        "impactScore": 3.6,
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  "published": "2026-05-28T06:16:29.493",
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.