{"id":"DEBIAN-CVE-2026-92289","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.  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.","modified":"2026-09-26T16:00:10.346215840Z","published":"2026-09-25T01:16:48.943Z","upstream":["CVE-2026-92289"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-92289"}],"affected":[{"package":{"name":"lemonldap-ng","ecosystem":"Debian:13","purl":"pkg:deb/debian/lemonldap-ng?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.21.2+ds-1","2.21.2+ds-1+deb13u1","2.21.2+ds-1+deb13u2","2.21.2+ds-1+deb13u3","2.21.2+ds-2","2.21.3+ds-1","2.21.3+ds-1~bpo12+1","2.21.3+ds-1~bpo13+1","2.22.0+ds-1","2.22.0+ds-2","2.22.0+ds-2~bpo13+1","2.22.1+ds-1","2.22.1+ds-1~bpo13+1","2.22.2+ds-1","2.22.2+ds-1~bpo13+1","2.22.3+ds-1","2.22.3+ds-1~bpo13+1","2.23.0+ds-1","2.23.0+ds-2","2.23.0+ds-3","2.23.0+ds-3~bpo13+1","2.23.0+ds-4","2.23.1+ds-1","2.23.2+ds-1","2.23.2+ds-1~bpo13+1","2.23.2+ds-2","2.23.3+ds-1","2.23.4+ds-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-92289.json"}}],"schema_version":"1.9.0"}