CPANSA-Lemonldap-NG-Portal-2026-92288: Lemonldap-NG-Portal vulnerability
| Publisher |
giterlizzi |
Document category |
csaf_security_advisory |
| Initial release date |
2026-09-25T00:00:00 |
Engine |
CSAF Perl Toolkit 0.26 |
| Current release date |
2026-09-25T00:00:00 |
Build Date |
|
| Current version |
1 |
Status |
final |
| CVSS v3.1 Base Score |
9.1
|
Severity |
Critical
|
| Original language |
|
Language |
en |
| Also referred to |
|
Vulnerability Description
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.
Vulnerabilities
CVE-2026-92288
Vulnerability DescriptionLemonldap::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.
Product status
Known affected
| Product |
Score |
| Lemonldap-NG-Portal greater than or equal 2.20.0 and less than 2.21.6 |
|
| Lemonldap-NG-Portal greater than or equal 2.22.0 and less than 2.23.4 |
|
Fixed
- Lemonldap-NG-Portal greater than or equal 2.21.6 and less than 2.22.0
- Lemonldap-NG-Portal greater than or equal 2.23.4
giterlizzi
Namespace: https://github.com/giterlizzi/
gdt@cpan.org
References
Revision history
| Version |
Date of the revision |
Summary of the revision |
| 1 |
Fri Sep 25 00:00:00 2026 |
First release |
Sharing rules
TLP:WHITE
For the TLP version see: https://www.first.org/tlp/