UBUNTU-CVE-2026-92289 (CVE-2026-92289)
Vulnerability from osv_ubuntu – Published: 2026-09-25 01:16 – Updated: 2026-09-30 21:38 – Source website
VLAI
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.
Severity
9.1 (Critical)
N/A (UNKNOWN)
References
{
"affected": [
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "lemonldap-ng",
"binary_version": "1.4.6-3"
},
{
"binary_name": "liblemonldap-ng-common-perl",
"binary_version": "1.4.6-3"
},
{
"binary_name": "liblemonldap-ng-conf-perl",
"binary_version": "1.4.6-3"
},
{
"binary_name": "liblemonldap-ng-handler-perl",
"binary_version": "1.4.6-3"
},
{
"binary_name": "liblemonldap-ng-manager-perl",
"binary_version": "1.4.6-3"
},
{
"binary_name": "liblemonldap-ng-portal-perl",
"binary_version": "1.4.6-3"
}
]
},
"package": {
"ecosystem": "Ubuntu:16.04:LTS",
"name": "lemonldap-ng",
"purl": "pkg:deb/ubuntu/lemonldap-ng@1.4.6-3?arch=source\u0026distro=xenial"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.3.3-1",
"1.4.6-1",
"1.4.6-2",
"1.4.6-3"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "lemonldap-ng",
"binary_version": "1.9.16-2"
},
{
"binary_name": "lemonldap-ng-fastcgi-server",
"binary_version": "1.9.16-2"
},
{
"binary_name": "lemonldap-ng-handler",
"binary_version": "1.9.16-2"
},
{
"binary_name": "liblemonldap-ng-common-perl",
"binary_version": "1.9.16-2"
},
{
"binary_name": "liblemonldap-ng-handler-perl",
"binary_version": "1.9.16-2"
},
{
"binary_name": "liblemonldap-ng-manager-perl",
"binary_version": "1.9.16-2"
},
{
"binary_name": "liblemonldap-ng-portal-perl",
"binary_version": "1.9.16-2"
}
]
},
"package": {
"ecosystem": "Ubuntu:18.04:LTS",
"name": "lemonldap-ng",
"purl": "pkg:deb/ubuntu/lemonldap-ng@1.9.16-2?arch=source\u0026distro=bionic"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.9.10-1",
"1.9.13-2",
"1.9.14-1",
"1.9.15-1",
"1.9.16-2"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "lemonldap-ng",
"binary_version": "2.0.7+ds-2"
},
{
"binary_name": "lemonldap-ng-fastcgi-server",
"binary_version": "2.0.7+ds-2"
},
{
"binary_name": "lemonldap-ng-handler",
"binary_version": "2.0.7+ds-2"
},
{
"binary_name": "lemonldap-ng-uwsgi-app",
"binary_version": "2.0.7+ds-2"
},
{
"binary_name": "liblemonldap-ng-common-perl",
"binary_version": "2.0.7+ds-2"
},
{
"binary_name": "liblemonldap-ng-handler-perl",
"binary_version": "2.0.7+ds-2"
},
{
"binary_name": "liblemonldap-ng-manager-perl",
"binary_version": "2.0.7+ds-2"
},
{
"binary_name": "liblemonldap-ng-portal-perl",
"binary_version": "2.0.7+ds-2"
}
]
},
"package": {
"ecosystem": "Ubuntu:20.04:LTS",
"name": "lemonldap-ng",
"purl": "pkg:deb/ubuntu/lemonldap-ng@2.0.7+ds-2?arch=source\u0026distro=focal"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.0.5+ds-2",
"2.0.6+ds-2",
"2.0.7+ds-2"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "lemonldap-ng",
"binary_version": "2.0.13+ds-3ubuntu1"
},
{
"binary_name": "lemonldap-ng-fastcgi-server",
"binary_version": "2.0.13+ds-3ubuntu1"
},
{
"binary_name": "lemonldap-ng-handler",
"binary_version": "2.0.13+ds-3ubuntu1"
},
{
"binary_name": "lemonldap-ng-uwsgi-app",
"binary_version": "2.0.13+ds-3ubuntu1"
},
{
"binary_name": "liblemonldap-ng-common-perl",
"binary_version": "2.0.13+ds-3ubuntu1"
},
{
"binary_name": "liblemonldap-ng-handler-perl",
"binary_version": "2.0.13+ds-3ubuntu1"
},
{
"binary_name": "liblemonldap-ng-manager-perl",
"binary_version": "2.0.13+ds-3ubuntu1"
},
{
"binary_name": "liblemonldap-ng-portal-perl",
"binary_version": "2.0.13+ds-3ubuntu1"
}
]
},
"package": {
"ecosystem": "Ubuntu:22.04:LTS",
"name": "lemonldap-ng",
"purl": "pkg:deb/ubuntu/lemonldap-ng@2.0.13+ds-3ubuntu1?arch=source\u0026distro=jammy"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.0.11+ds-4",
"2.0.13+ds-3",
"2.0.13+ds-3ubuntu1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "lemonldap-ng",
"binary_version": "2.18.2+ds-1"
},
{
"binary_name": "lemonldap-ng-fastcgi-server",
"binary_version": "2.18.2+ds-1"
},
{
"binary_name": "lemonldap-ng-handler",
"binary_version": "2.18.2+ds-1"
},
{
"binary_name": "lemonldap-ng-uwsgi-app",
"binary_version": "2.18.2+ds-1"
},
{
"binary_name": "liblemonldap-ng-common-perl",
"binary_version": "2.18.2+ds-1"
},
{
"binary_name": "liblemonldap-ng-handler-perl",
"binary_version": "2.18.2+ds-1"
},
{
"binary_name": "liblemonldap-ng-manager-perl",
"binary_version": "2.18.2+ds-1"
},
{
"binary_name": "liblemonldap-ng-portal-perl",
"binary_version": "2.18.2+ds-1"
},
{
"binary_name": "liblemonldap-ng-ssoaas-apache-client-perl",
"binary_version": "2.18.2+ds-1"
}
]
},
"package": {
"ecosystem": "Ubuntu:24.04:LTS",
"name": "lemonldap-ng",
"purl": "pkg:deb/ubuntu/lemonldap-ng@2.18.2+ds-1?arch=source\u0026distro=noble"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.16.2+ds-1",
"2.17.1+ds-1",
"2.17.2+ds-1",
"2.17.2+ds-2",
"2.18.1+ds-1",
"2.18.2+ds-1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "lemonldap-ng",
"binary_version": "2.22.2+ds-1"
},
{
"binary_name": "lemonldap-ng-fastcgi-server",
"binary_version": "2.22.2+ds-1"
},
{
"binary_name": "lemonldap-ng-handler",
"binary_version": "2.22.2+ds-1"
},
{
"binary_name": "lemonldap-ng-uwsgi-app",
"binary_version": "2.22.2+ds-1"
},
{
"binary_name": "liblemonldap-ng-common-perl",
"binary_version": "2.22.2+ds-1"
},
{
"binary_name": "liblemonldap-ng-handler-perl",
"binary_version": "2.22.2+ds-1"
},
{
"binary_name": "liblemonldap-ng-manager-perl",
"binary_version": "2.22.2+ds-1"
},
{
"binary_name": "liblemonldap-ng-portal-perl",
"binary_version": "2.22.2+ds-1"
},
{
"binary_name": "liblemonldap-ng-ssoaas-apache-client-perl",
"binary_version": "2.22.2+ds-1"
}
]
},
"package": {
"ecosystem": "Ubuntu:26.04:LTS",
"name": "lemonldap-ng",
"purl": "pkg:deb/ubuntu/lemonldap-ng@2.22.2+ds-1?arch=source\u0026distro=resolute"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.21.0+ds-3",
"2.22.0+ds-2",
"2.22.1+ds-1",
"2.22.2+ds-1"
]
}
],
"aliases": [],
"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\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": "UBUNTU-CVE-2026-92289",
"modified": "2026-09-30T21:38:28Z",
"published": "2026-09-25T01:16:00Z",
"references": [
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-92289"
},
{
"type": "REPORT",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-92289"
},
{
"type": "REPORT",
"url": "https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/3719"
}
],
"related": [],
"schema_version": "1.7.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"upstream": [
"CVE-2026-92289"
]
}
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Sightings
| Author | Source | Type | Date | Other |
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Nomenclature
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vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
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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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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