{"id":"CVE-2026-92289","state":"PUBLISHED","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","description":"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'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.","publishedAt":"2026-09-25T00:15:49.826Z","updatedAt":"2026-09-26T22:29:08.052Z","severity":{"score":9.1,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","source":"CISA-ADP"},"assigner":"CPANSec","products":["Lemonldap-NG-Portal"],"affected":[{"packageName":"Lemonldap-NG-Portal","packageURL":"pkg:cpan/Lemonldap-NG-Portal","defaultStatus":"unaffected","versions":[{"version":"2.23.0","status":"affected","lessThan":"2.23.4","versionType":"custom"}],"collectionURL":"https://cpan.org/modules","modules":["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"}],"references":["https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/3719","https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/releases/v2.23.4","http://www.openwall.com/lists/oss-security/2026/09/25/2"],"weaknesses":["CWE-1390"],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/92xxx/CVE-2026-92289.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-92289","state":"PUBLISHED","datePublished":"2026-09-25T00:15:49.826Z","dateUpdated":"2026-09-26T22:29:08.052Z","assignerShortName":"CPANSec","assignerOrgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","dateReserved":"2026-09-15T23:43:48.309Z"},"containers":{"cna":{"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","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'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."}],"affected":[{"packageName":"Lemonldap-NG-Portal","packageURL":"pkg:cpan/Lemonldap-NG-Portal","defaultStatus":"unaffected","versions":[{"version":"2.23.0","status":"affected","lessThan":"2.23.4","versionType":"custom"}],"collectionURL":"https://cpan.org/modules","modules":["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"}],"references":[{"url":"https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/3719","tags":["issue-tracking"]},{"url":"https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/releases/v2.23.4","tags":["release-notes"]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1390","description":"CWE-1390 Weak Authentication","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"CPANSec","orgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","dateUpdated":"2026-09-25T00:15:49.826Z"},"solutions":[{"lang":"en","value":"Upgrade to Lemonldap-NG-Portal 2.23.4 or later."}],"source":{"discovery":"UNKNOWN"},"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"}},"adp":[{"title":"CVE Program Container","references":[{"url":"http://www.openwall.com/lists/oss-security/2026/09/25/2"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-09-25T02:10:01.838Z"}},{"title":"CISA ADP Vulnrichment","references":[{"url":"https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/3719","tags":["exploit"]}],"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":9.1,"attackVector":"NETWORK","baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-09-25T15:38:54.575555Z","id":"CVE-2026-92289","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-26T22:29:08.052Z"}}]}}}