Description
OpenID Connect Issuer in LemonLDAP::NG 2.x through 2.0.5 may allow an attacker to bypass access control rules via a crafted OpenID Connect authorization request. To be vulnerable, there must exist an OIDC Relaying party within the LemonLDAP configuration with weaker access control rules than the target RP, and no filtering on redirection URIs.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | lemonldap-ng | 2.0.6+ds-1 | — |
| Debian 13 | lemonldap-ng | 2.0.6+ds-1 | — |
| Debian 12 | lemonldap-ng | 2.0.6+ds-1 | — |
| Debian 10 | lemonldap-ng | 2.0.2+ds-7+deb10u2 | DSA-4533-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | lemonldap-ng | No fix yet | — |
| Ubuntu 16.04 LTS | lemonldap-ng | No fix yet | — |
Advisories 1
- DSA-4533-1 lemonldap-ng - security update Debian Security (DSA / DLA) · Mar 9, 2026