FKIE_CVE-2026-92288

Vulnerability from fkie_nvd - Published: 2026-09-25 01:16 - Updated: 2026-09-25 13:22
Severity
Summary
Lemonldap::NG::Portal versions from 2.20.0 before 2.21.6, from 2.22.0 before 2.23.4 for Perl allow unauthenticated OAuth2 token introspection because checkEndPointAuthenticationCredentials does not verify the client secret of a public Relying Party. checkEndPointAuthenticationCredentials() skips the secret comparison for a Relying Party marked public and still returns the authentication method deduced from the request, client_secret_basic or client_secret_post. introspection() rejects a caller only when that method is missing or none, so a request carrying a public client_id and an arbitrary or empty secret passes the endpoint's authentication check. An attacker who holds an access token and knows the client_id of any public Relying Party can confirm the token is active and read its metadata, including scope, audience, expiry and the sub claim. The sub claim is computed with the calling Relying Party's user identifier attribute, so an attacker can translate a user identifier from one Relying Party to another, defeating per-client and pseudonymous identifiers.
References
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/releases/v2.21.6
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/releases/v2.23.4
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/3719
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/3721
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/09/25/1
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Lemonldap::NG::Portal"
          ],
          "packageName": "Lemonldap-NG-Portal",
          "packageURL": "pkg:cpan/Lemonldap-NG-Portal",
          "programFiles": [
            "lib/Lemonldap/NG/Portal/Lib/OpenIDConnect.pm",
            "lib/Lemonldap/NG/Portal/Issuer/OpenIDConnect.pm"
          ],
          "programRoutines": [
            {
              "name": "Lemonldap::NG::Portal::Lib::OpenIDConnect::checkEndPointAuthenticationCredentials"
            },
            {
              "name": "Lemonldap::NG::Portal::Issuer::OpenIDConnect::introspection"
            }
          ],
          "repo": "https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng",
          "versions": [
            {
              "lessThan": "2.21.6",
              "status": "affected",
              "version": "2.20.0",
              "versionType": "custom"
            },
            {
              "lessThan": "2.23.4",
              "status": "affected",
              "version": "2.22.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Lemonldap::NG::Portal versions from 2.20.0 before 2.21.6, from 2.22.0 before 2.23.4 for Perl allow unauthenticated OAuth2 token introspection because checkEndPointAuthenticationCredentials does not verify the client secret of a public Relying Party.\n\ncheckEndPointAuthenticationCredentials() skips the secret comparison for a Relying Party marked public and still returns the authentication method deduced from the request, client_secret_basic or client_secret_post. introspection() rejects a caller only when that method is missing or none, so a request carrying a public client_id and an arbitrary or empty secret passes the endpoint\u0027s authentication check.\n\nAn attacker who holds an access token and knows the client_id of any public Relying Party can confirm the token is active and read its metadata, including scope, audience, expiry and the sub claim. The sub claim is computed with the calling Relying Party\u0027s user identifier attribute, so an attacker can translate a user identifier from one Relying Party to another, defeating per-client and pseudonymous identifiers."
    }
  ],
  "id": "CVE-2026-92288",
  "lastModified": "2026-09-25T13:22:04.673",
  "metrics": {},
  "published": "2026-09-25T01:16:48.820",
  "references": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/releases/v2.21.6"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/releases/v2.23.4"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/3719"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/3721"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/09/25/1"
    }
  ],
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-1390"
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary"
    }
  ]
}



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