Vulnerability-Lookup

GHSA-4X37-HW65-52W8

Vulnerability from github – Published: 2026-05-19 12:31 – Updated: 2026-05-20 18:31

Details

A flaw was found in Keycloak. This access control vulnerability in Keycloak's OpenID Connect (OIDC) token introspection endpoint allows a confidential client to bypass audience restrictions. An attacker-controlled client with valid credentials can retrieve sensitive token claims intended for other resource servers, compromising the confidentiality of lightweight access tokens. This issue can be exploited remotely by any confidential client in the realm with valid credentials.

Severity ?

6.5 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-37979"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-284"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-19T12:16:18Z",
    "severity": "MODERATE"
  },
  "details": "A flaw was found in Keycloak. This access control vulnerability in Keycloak\u0027s OpenID Connect (OIDC) token introspection endpoint allows a confidential client to bypass audience restrictions. An attacker-controlled client with valid credentials can retrieve sensitive token claims intended for other resource servers, compromising the confidentiality of lightweight access tokens. This issue can be exploited remotely by any confidential client in the realm with valid credentials.",
  "id": "GHSA-4x37-hw65-52w8",
  "modified": "2026-05-20T18:31:32Z",
  "published": "2026-05-19T12:31:39Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-37979"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:19596"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:19597"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-37979"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2455328"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-37979 (GCVE-0-2026-37979)

Vulnerability from cvelistv5 – Published: 2026-05-19 10:52 – Updated: 2026-05-20 16:08

Title

Keycloak: keycloak: information disclosure via oidc token introspection endpoint audience bypass

Summary

Severity ?

6.5 (Medium)


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

CWE

CWE-284 - Improper Access Control

Assigner

redhat

References

4 references

URL	Tags
https://access.redhat.com/errata/RHSA-2026:19596	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:19597	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-37979	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2455328	issue-trackingx_refsource_REDHAT

Impacted products

4 products

Vendor	Product	Version
Red Hat	Red Hat build of Keycloak 26.4	Unaffected: 26.4.12-1 , < * (rpm) cpe:/a:redhat:build_keycloak:26.4::el9
Red Hat	Red Hat build of Keycloak 26.4	Unaffected: 26.4-17 , < * (rpm) cpe:/a:redhat:build_keycloak:26.4::el9
Red Hat	Red Hat build of Keycloak 26.4	Unaffected: 26.4-17 , < * (rpm) cpe:/a:redhat:build_keycloak:26.4::el9
Red Hat	Red Hat build of Keycloak 26.4.12	cpe:/a:redhat:build_keycloak:26.4::el9

Date Public ?

2026-05-19 00:00

Credits

Red Hat would like to thank Herdiyan Adam Putra for reporting this issue.

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-37979",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-19T13:39:36.285295Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-284",
                "description": "CWE-284 Improper Access Control",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-19T13:40:07.406Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "defaultStatus": "affected",
          "packageName": "rhbk/keycloak-operator-bundle",
          "product": "Red Hat build of Keycloak 26.4",
          "vendor": "Red Hat",
          "versions": [
            {
              "lessThan": "*",
              "status": "unaffected",
              "version": "26.4.12-1",
              "versionType": "rpm"
            }
          ]
        },
        {
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "defaultStatus": "affected",
          "packageName": "rhbk/keycloak-rhel9",
          "product": "Red Hat build of Keycloak 26.4",
          "vendor": "Red Hat",
          "versions": [
            {
              "lessThan": "*",
              "status": "unaffected",
              "version": "26.4-17",
              "versionType": "rpm"
            }
          ]
        },
        {
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "defaultStatus": "affected",
          "packageName": "rhbk/keycloak-rhel9-operator",
          "product": "Red Hat build of Keycloak 26.4",
          "vendor": "Red Hat",
          "versions": [
            {
              "lessThan": "*",
              "status": "unaffected",
              "version": "26.4-17",
              "versionType": "rpm"
            }
          ]
        },
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ],
          "defaultStatus": "unaffected",
          "packageName": "rhbk/keycloak-rhel9",
          "product": "Red Hat build of Keycloak 26.4.12",
          "vendor": "Red Hat"
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Red Hat would like to thank Herdiyan Adam Putra for reporting this issue."
        }
      ],
      "datePublic": "2026-05-19T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "A flaw was found in Keycloak. This access control vulnerability in Keycloak\u0027s OpenID Connect (OIDC) token introspection endpoint allows a confidential client to bypass audience restrictions. An attacker-controlled client with valid credentials can retrieve sensitive token claims intended for other resource servers, compromising the confidentiality of lightweight access tokens. This issue can be exploited remotely by any confidential client in the realm with valid credentials."
        }
      ],
      "metrics": [
        {
          "other": {
            "content": {
              "namespace": "https://access.redhat.com/security/updates/classification/",
              "value": "Moderate"
            },
            "type": "Red Hat severity rating"
          }
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-20T16:08:52.747Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "name": "RHSA-2026:19596",
          "tags": [
            "vendor-advisory",
            "x_refsource_REDHAT"
          ],
          "url": "https://access.redhat.com/errata/RHSA-2026:19596"
        },
        {
          "name": "RHSA-2026:19597",
          "tags": [
            "vendor-advisory",
            "x_refsource_REDHAT"
          ],
          "url": "https://access.redhat.com/errata/RHSA-2026:19597"
        },
        {
          "tags": [
            "vdb-entry",
            "x_refsource_REDHAT"
          ],
          "url": "https://access.redhat.com/security/cve/CVE-2026-37979"
        },
        {
          "name": "RHBZ#2455328",
          "tags": [
            "issue-tracking",
            "x_refsource_REDHAT"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2455328"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-04-06T07:57:53.307Z",
          "value": "Reported to Red Hat."
        },
        {
          "lang": "en",
          "time": "2026-05-19T00:00:00.000Z",
          "value": "Made public."
        }
      ],
      "title": "Keycloak: keycloak: information disclosure via oidc token introspection endpoint audience bypass",
      "workarounds": [
        {
          "lang": "en",
          "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."
        }
      ],
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2026-37979",
    "datePublished": "2026-05-19T10:52:30.442Z",
    "dateReserved": "2026-04-06T07:48:39.722Z",
    "dateUpdated": "2026-05-20T16:08:52.747Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Action not permitted

GHSA-4X37-HW65-52W8

CVE-2026-37979 (GCVE-0-2026-37979)

Tags

Sightings

Nomenclature