CVE-2026-40166 (GCVE-0-2026-40166)

Vulnerability from cvelistv5 – Published: 2026-05-22 18:52 – Updated: 2026-05-26 18:47
VLAI
Title
authentik: Non-admin user can retrieve confidential OAuth client_secret via /api/v3/oauth2/access_tokens/
Summary
authentik is an open-source identity provider. In versions prior to 2025.12.5 and 2026.2.0-rc1 through 2026.2.2, authenticated non-admin users with at least one OAuth2 access token can retrieve the client_secret of confidential OAuth2 providers they have previously authenticated against, exposing sensitive information to users without the correct permissions. This logic is GET /api/v3/oauth2/access_tokens/. The API response includes a nested provider object containing client_id and client_secret for providers configured with client_type: confidential, which should not be accessible to low-privilege users. This issue has been fixed in versions 2025.12.5 and 2026.2.3.
Severity
7.1 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N
CWE
  • CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-863 - Incorrect Authorization
Assigner
References
Impacted products
Vendor Product Version
goauthentik authentik Affected: < 2025.12.5
Affected: >= 2026.2.0-rc1, < 2026.2.3
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-40166",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-26T18:47:45.180359Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-26T18:47:57.418Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "authentik",
          "vendor": "goauthentik",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2025.12.5"
            },
            {
              "status": "affected",
              "version": "\u003e= 2026.2.0-rc1, \u003c 2026.2.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "authentik is an open-source identity provider. In versions prior to 2025.12.5 and 2026.2.0-rc1 through 2026.2.2, authenticated non-admin users with at least one OAuth2 access token can retrieve the client_secret of confidential OAuth2 providers they have previously authenticated against, exposing sensitive information to users without the correct permissions. This logic is GET /api/v3/oauth2/access_tokens/. The API response includes a nested provider object containing client_id and client_secret for providers configured with client_type: confidential, which should not be accessible to low-privilege users. This issue has been fixed in versions 2025.12.5 and 2026.2.3."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-200",
              "description": "CWE-200: Exposure of Sensitive Information to an Unauthorized Actor",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-863",
              "description": "CWE-863: Incorrect Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-22T18:52:46.650Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/goauthentik/authentik/security/advisories/GHSA-hhpc-rqgm-pxj4",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/goauthentik/authentik/security/advisories/GHSA-hhpc-rqgm-pxj4"
        },
        {
          "name": "https://github.com/goauthentik/authentik/releases/tag/version%2F2025.12.5",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/goauthentik/authentik/releases/tag/version%2F2025.12.5"
        },
        {
          "name": "https://github.com/goauthentik/authentik/releases/tag/version%2F2026.2.3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/goauthentik/authentik/releases/tag/version%2F2026.2.3"
        }
      ],
      "source": {
        "advisory": "GHSA-hhpc-rqgm-pxj4",
        "discovery": "UNKNOWN"
      },
      "title": "authentik: Non-admin user can retrieve confidential OAuth client_secret via /api/v3/oauth2/access_tokens/"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-40166",
    "datePublished": "2026-05-22T18:52:46.650Z",
    "dateReserved": "2026-04-09T19:31:56.014Z",
    "dateUpdated": "2026-05-26T18:47:57.418Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-40166",
      "date": "2026-05-29",
      "epss": "0.00011",
      "percentile": "0.0149"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-40166\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-05-26T18:47:45.180359Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-05-26T18:47:53.997Z\"}}], \"cna\": {\"title\": \"authentik: Non-admin user can retrieve confidential OAuth client_secret via /api/v3/oauth2/access_tokens/\", \"source\": {\"advisory\": \"GHSA-hhpc-rqgm-pxj4\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV4_0\": {\"version\": \"4.0\", \"baseScore\": 7.1, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"LOW\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"NONE\", \"subConfidentialityImpact\": \"LOW\", \"vulnConfidentialityImpact\": \"HIGH\"}}], \"affected\": [{\"vendor\": \"goauthentik\", \"product\": \"authentik\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 2025.12.5\"}, {\"status\": \"affected\", \"version\": \"\u003e= 2026.2.0-rc1, \u003c 2026.2.3\"}]}], \"references\": [{\"url\": \"https://github.com/goauthentik/authentik/security/advisories/GHSA-hhpc-rqgm-pxj4\", \"name\": \"https://github.com/goauthentik/authentik/security/advisories/GHSA-hhpc-rqgm-pxj4\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/goauthentik/authentik/releases/tag/version%2F2025.12.5\", \"name\": \"https://github.com/goauthentik/authentik/releases/tag/version%2F2025.12.5\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/goauthentik/authentik/releases/tag/version%2F2026.2.3\", \"name\": \"https://github.com/goauthentik/authentik/releases/tag/version%2F2026.2.3\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"authentik is an open-source identity provider. In versions prior to 2025.12.5 and 2026.2.0-rc1 through 2026.2.2, authenticated non-admin users with at least one OAuth2 access token can retrieve the client_secret of confidential OAuth2 providers they have previously authenticated against, exposing sensitive information to users without the correct permissions. This logic is GET /api/v3/oauth2/access_tokens/. The API response includes a nested provider object containing client_id and client_secret for providers configured with client_type: confidential, which should not be accessible to low-privilege users. This issue has been fixed in versions 2025.12.5 and 2026.2.3.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-200\", \"description\": \"CWE-200: Exposure of Sensitive Information to an Unauthorized Actor\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-863\", \"description\": \"CWE-863: Incorrect Authorization\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-05-22T18:52:46.650Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-40166\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-05-26T18:47:57.418Z\", \"dateReserved\": \"2026-04-09T19:31:56.014Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-05-22T18:52:46.650Z\", \"assignerShortName\": \"GitHub_M\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.