Medium

Keycloak: keycloak: denial of service due to excessive samlrequest decompression

Type: advisorySource: Official CVE List1 source record

A flaw was found in Keycloak. An unauthenticated remote attacker can trigger an application level Denial of Service (DoS) by sending a highly compressed SAMLRequest through the SAML Redirect Binding. The server fails to enforce size limits during DEFLATE decompression, leading to an OutOfMemoryError (OOM) and subsequent process termination. This vulnerability allows an attacker to disrupt the availability of the service.

Announced 18 Mar 2026Source revision 1

Original source ↗

CVE-2026-2575

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-2026-2575

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 26.4.10

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 Single Sign-On 7.6.13

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 Single Sign-On 7.6 for RHEL 7

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 Single Sign-On 7.6 for RHEL 8

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 Single Sign-On 7.6 for RHEL 9

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

RHEL-8 based Middleware Containers

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

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "cpes": [
      "cpe:/a:redhat:build_keycloak:26.4::el9"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat build of Keycloak 26.4",
    "versions": [
      {
        "status": "unaffected",
        "version": "26.4.10-1",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rhbk/keycloak-operator-bundle",
    "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",
    "versions": [
      {
        "status": "unaffected",
        "version": "26.4-12",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rhbk/keycloak-rhel9",
    "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",
    "versions": [
      {
        "status": "unaffected",
        "version": "26.4-12",
        "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 26.4.10",
    "packageName": "rhbk/keycloak-rhel9",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "unaffected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:red_hat_single_sign_on:7.6"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Single Sign-On 7.6.13",
    "packageName": "keycloak-services",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "unaffected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:red_hat_single_sign_on:7.6::el7"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Single Sign-On 7.6 for RHEL 7",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:18.0.20-1.redhat_00001.1.el7sso",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rh-sso7-keycloak",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:red_hat_single_sign_on:7.6::el8"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Single Sign-On 7.6 for RHEL 8",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:18.0.20-1.redhat_00001.1.el8sso",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rh-sso7-keycloak",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:red_hat_single_sign_on:7.6::el9"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Single Sign-On 7.6 for RHEL 9",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:18.0.20-1.redhat_00001.1.el9sso",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rh-sso7-keycloak",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:rhosemc:1.0::el8"
    ],
    "vendor": "Red Hat",
    "product": "RHEL-8 based Middleware Containers",
    "versions": [
      {
        "status": "unaffected",
        "version": "7.6-85",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "rh-sso-7/sso76-openshift-rhel8",
    "collectionURL": "https://catalog.redhat.com/software/containers/",
    "defaultStatus": "affected"
  }
]

Related CVEs: CVE-2026-2575
Source reference: /cveMetadata/cveId

Publisher severity

medium

Source reference: /containers/cna/metrics

Event: #9448 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 23:17:53 GMT
Publisher date: Wed, 18 Mar 2026 03:19:09 GMT

Read the original announcement