Vulnerability-Lookup

GHSA-VW4X-93XP-F6F3

Vulnerability from github – Published: 2026-09-25 03:31 – Updated: 2026-09-25 03:31

Details

With oidcRPMetaDataOptionsRequirePKCE set to 2, the authorization endpoint issues a code even when the request carries no code_challenge, and token() admits the exchange as long as a challenge was stored or an authentication method was returned for the caller. checkEndPointAuthenticationCredentials() skips the secret comparison for a Relying Party marked public and still returns the method deduced from the request, so any Basic or form credential satisfies the secret branch. validatePKCEChallenge() then passes, because neither a challenge nor a verifier is present.

An attacker who intercepts an authorization code issued to a public Relying Party can exchange it for the user's access, ID and refresh tokens by replaying the client_id with an arbitrary secret, which is the attack PKCE prevents. Dynamic client registration creates every Relying Party in this mode.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-92289"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1390"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-25T01:16:48Z",
    "severity": null
  },
  "details": "Lemonldap::NG::Portal versions from 2.23.0 before 2.23.4 for Perl allow a PKCE bypass for public Relying Parties in \"PKCE or secret\" mode because checkEndPointAuthenticationCredentials does not verify the client secret.\n\nWith oidcRPMetaDataOptionsRequirePKCE set to 2, the authorization endpoint issues a code even when the request carries no code_challenge, and token() admits the exchange as long as a challenge was stored or an authentication method was returned for the caller. checkEndPointAuthenticationCredentials() skips the secret comparison for a Relying Party marked public and still returns the method deduced from the request, so any Basic or form credential satisfies the secret branch. validatePKCEChallenge() then passes, because neither a challenge nor a verifier is present.\n\nAn attacker who intercepts an authorization code issued to a public Relying Party can exchange it for the user\u0027s access, ID and refresh tokens by replaying the client_id with an arbitrary secret, which is the attack PKCE prevents. Dynamic client registration creates every Relying Party in this mode.",
  "id": "GHSA-vw4x-93xp-f6f3",
  "modified": "2026-09-25T03:31:00Z",
  "published": "2026-09-25T03:31:00Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-92289"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/releases/v2.23.4"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/3719"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/09/25/2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-92289 (GCVE-0-2026-92289)

Vulnerability from cvelistv5 – Published: 2026-09-25 00:15 – Updated: 2026-09-25 15:41

Title

Summary

Lemonldap::NG::Portal versions from 2.23.0 before 2.23.4 for Perl allow a PKCE bypass for public Relying Parties in "PKCE or secret" mode because checkEndPointAuthenticationCredentials does not verify the client secret. With oidcRPMetaDataOptionsRequirePKCE set to 2, the authorization endpoint issues a code even when the request carries no code_challenge, and token() admits the exchange as long as a challenge was stored or an authentication method was returned for the caller. checkEndPointAuthenticationCredentials() skips the secret comparison for a Relying Party marked public and still returns the method deduced from the request, so any Basic or form credential satisfies the secret branch. validatePKCEChallenge() then passes, because neither a challenge nor a verifier is present. An attacker who intercepts an authorization code issued to a public Relying Party can exchange it for the user's access, ID and refresh tokens by replaying the client_id with an arbitrary secret, which is the attack PKCE prevents. Dynamic client registration creates every Relying Party in this mode.

Severity

No CVSS data available.

SSVC

Exploitation: poc Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-25 15:38 UTC

CWE

CWE-1390 - Weak Authentication

Assigner

CPANSec redhat root

References

3 references

URL	Tags
https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/…	issue-tracking
https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/…	release-notes
http://www.openwall.com/lists/oss-security/2026/09/25/2

Impacted products

1 product

Vendor	Product	Version
		Affected: 2.23.0 , < 2.23.4 (custom)

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-09-25T02:10:01.838Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/09/25/2"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-92289",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-25T15:38:54.575555Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-25T15:41:15.228Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/3719"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "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::token"
            }
          ],
          "repo": "https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng",
          "versions": [
            {
              "lessThan": "2.23.4",
              "status": "affected",
              "version": "2.23.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Lemonldap::NG::Portal versions from 2.23.0 before 2.23.4 for Perl allow a PKCE bypass for public Relying Parties in \"PKCE or secret\" mode because checkEndPointAuthenticationCredentials does not verify the client secret.\n\nWith oidcRPMetaDataOptionsRequirePKCE set to 2, the authorization endpoint issues a code even when the request carries no code_challenge, and token() admits the exchange as long as a challenge was stored or an authentication method was returned for the caller. checkEndPointAuthenticationCredentials() skips the secret comparison for a Relying Party marked public and still returns the method deduced from the request, so any Basic or form credential satisfies the secret branch. validatePKCEChallenge() then passes, because neither a challenge nor a verifier is present.\n\nAn attacker who intercepts an authorization code issued to a public Relying Party can exchange it for the user\u0027s access, ID and refresh tokens by replaying the client_id with an arbitrary secret, which is the attack PKCE prevents. Dynamic client registration creates every Relying Party in this mode."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1390",
              "description": "CWE-1390 Weak Authentication",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-25T00:15:49.826Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "tags": [
            "issue-tracking"
          ],
          "url": "https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/3719"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/releases/v2.23.4"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to Lemonldap-NG-Portal 2.23.4 or later."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Lemonldap::NG::Portal versions from 2.23.0 before 2.23.4 for Perl allow a PKCE bypass for public Relying Parties in \"PKCE or secret\" mode because checkEndPointAuthenticationCredentials does not verify the client secret",
      "workarounds": [
        {
          "lang": "en",
          "value": "For deployments that cannot upgrade to 2.23.4, set RequirePKCE to 1 on public Relying Parties so that a code challenge is always required. Relying Parties created through dynamic registration are always in \"PKCE or secret\" mode, so that endpoint has to be disabled as well."
        }
      ],
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-92289",
    "datePublished": "2026-09-25T00:15:49.826Z",
    "dateReserved": "2026-09-15T23:43:48.309Z",
    "dateUpdated": "2026-09-25T15:41:15.228Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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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.
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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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-VW4X-93XP-F6F3

CVE-2026-92289 (GCVE-0-2026-92289)

Tags

Sightings

Nomenclature

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