High

Keycloak-services: keycloak-services: unauthenticated dos via unbounded locale caching

Type: advisorySource: Official CVE List1 source record

A flaw was found in the theme localization endpoints of the keycloak-services component, which is the core service responsible for authentication flows and theme management in Keycloak. The issue occurs because the system accepts arbitrary locale tags from unauthenticated requests and stores them in a permanent in-memory cache without limits. An attacker can exploit this by sending a large number of unique locale tags, eventually causing the server to run out of memory and crash.

Announced 16 Sept 2026Group revision 1

Original source ↗

CVE-2026-79651

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-79651

Red Hat build of Keycloak 26.4

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat build of Keycloak 26.4

Source reference: /containers/cna/affected/1/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat build of Keycloak 26.4

Source reference: /containers/cna/affected/2/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat build of Keycloak 26.4.16

Source reference: /containers/cna/affected/3/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat build of Keycloak 26.4.16

Source reference: /containers/cna/affected/4/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat build of Keycloak 26.4.16

Source reference: /containers/cna/affected/5/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat build of Keycloak 26.6

Source reference: /containers/cna/affected/6/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat build of Keycloak 26.6

Source reference: /containers/cna/affected/7/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat build of Keycloak 26.6

Source reference: /containers/cna/affected/8/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat build of Keycloak 26.6.7

Source reference: /containers/cna/affected/9/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat build of Keycloak 26.6.7

Source reference: /containers/cna/affected/10/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat build of Keycloak 26.6.7

Source reference: /containers/cna/affected/11/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Single Sign-On 7

Source reference: /containers/cna/affected/12/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

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    ],
    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.4",
    "versions": [
      {
        "status": "unaffected",
        "version": "26.4.16-2",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rhbk/keycloak-operator-bundle",
    "collectionURL": "https://catalog.redhat.com/software/containers/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
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    ],
    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.4",
    "versions": [
      {
        "status": "unaffected",
        "version": "26.4-26",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rhbk/keycloak-rhel9",
    "collectionURL": "https://catalog.redhat.com/software/containers/",
    "defaultStatus": "affected"
  },
  {
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      "cpe:/a:redhat:build_keycloak:26.4::el9"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.4",
    "versions": [
      {
        "status": "unaffected",
        "version": "26.4-26",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rhbk/keycloak-rhel9-operator",
    "collectionURL": "https://catalog.redhat.com/software/containers/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:build_keycloak:26.4::el9"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.4.16",
    "packageName": "keycloak/rhbk-openshift-rhel9",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "unaffected"
  },
  {
    "cpes": [
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    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.4.16",
    "packageName": "keycloak-services",
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    "defaultStatus": "unaffected"
  },
  {
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    ],
    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.4.16",
    "packageName": "rhbk/keycloak-rhel9",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "unaffected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:build_keycloak:26.6::el9"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.6",
    "versions": [
      {
        "status": "unaffected",
        "version": "26.6.7-3",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rhbk/keycloak-operator-bundle",
    "collectionURL": "https://catalog.redhat.com/software/containers/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:build_keycloak:26.6::el9"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.6",
    "versions": [
      {
        "status": "unaffected",
        "version": "26.6-20",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rhbk/keycloak-rhel9",
    "collectionURL": "https://catalog.redhat.com/software/containers/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:build_keycloak:26.6::el9"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.6",
    "versions": [
      {
        "status": "unaffected",
        "version": "26.6-20",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rhbk/keycloak-rhel9-operator",
    "collectionURL": "https://catalog.redhat.com/software/containers/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:build_keycloak:26.6::el9"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.6.7",
    "packageName": "keycloak/rhbk-openshift-rhel9",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "unaffected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:build_keycloak:26.6::el9"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.6.7",
    "packageName": "keycloak-services",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "unaffected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:build_keycloak:26.6::el9"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.6.7",
    "packageName": "rhbk/keycloak-rhel9",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "unaffected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:red_hat_single_sign_on:7"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Single Sign-On 7",
    "packageName": "keycloak-services",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "unaffected"
  }
]

Related CVEs: CVE-2026-79651
Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event: #1994 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 21:11:10 GMT
Publisher date: Wed, 16 Sep 2026 14:55:09 GMT

Read the original announcement

Revision history

24 Oct 2026CVE-2026-79651 · Revision 1Source updated