Debian Updates Lemonldap::NG for Three Access-Control Flaws
Tech GuruQuick Answer
Debian 13's Lemonldap::NG package needs the DSA-6520-1 update for access-control bypass, authorization problems involving PKCE, and information disclosure. The listed fixed build is 2.21.2+ds-1+deb13u4. Plan the change around the applications that rely on this single-sign-on service.
Confirm Scope And Apply The Supported Fix
Next step: Inventory Lemonldap::NG nodes and dependent applications, then update from the supported trixie security repository. Retain a tested administrative recovery route if SSO becomes unavailable.
Last verified: 2026-09-28 UTC. Recheck the authoritative advisory and supported distribution channel before changing production.
Scope And Authority
| Product scope | Debian 13 (trixie) lemonldap-ng packages before 2.21.2+ds-1+deb13u4 |
|---|---|
| Advisory | DSA-6520-1 |
| CVEs | CVE-2026-92288, CVE-2026-92289, CVE-2026-95811 |
| Authoritative release date | 2026-09-27 17:23:56 UTC |
| Authority revision date | No separate material revision date stated by Debian; verified against the signed advisory announcement |
| Affected versions | Debian 13 (trixie) lemonldap-ng packages before 2.21.2+ds-1+deb13u4 |
| Fixed version | lemonldap-ng 2.21.2+ds-1+deb13u4 for Debian 13 (trixie) |
| CVSS base score | Not provided by the authority |
| CVSS severity | Not provided by the authority |
| Exploitation status | Not stated by the authority; no exploitation claim is inferred. |
What Changed
PKCE binds an authorization-code exchange to the client that initiated it. Debian identifies an authorization bypass in setups using that mechanism as one of three issues; do not assume every flaw has the same configuration prerequisite. The package fix applies to trixie, not automatically to unrelated upstream installations.
What To Validate Now
- Inventory. Locate Debian 13 (trixie) systems and containers with lemonldap-ng; record package version, repository, enabled services or consuming applications, exposure, owner, and dependencies.
- Establish applicability. Compare the installed package to DSA-6520-1 and the Debian Security Tracker. The advisory addresses the trixie package; do not infer scope for another Debian release or an upstream build.
- Remediate. Install lemonldap-ng 2.21.2+ds-1+deb13u4 for Debian 13 (trixie) through a supported Debian security repository, following Debian's current advisory and normal change control.
- Validate. Test sign-in, sign-out, session behavior, and required PKCE client flows with test accounts. Check that unauthorized roles still cannot reach protected applications. Validate all SSO nodes and redact tokens and session identifiers from retained evidence.
- Retain evidence. Preserve asset and owner identifiers, the applicability decision, before-and-after versions, change approval, installation output, validation results, and any exception or rollback record.
Operational Cautions
Use the exact supported release stream and repository. Test dependencies, clusters, integrations, and rollback before broad deployment; a CVSS rating or reachable feature is not evidence of exploitation.
Evidence To Retain
- Exact product, release stream, package or application version, enabled feature, environment, and accountable owner.
- UTC timestamps, authority revision, approved change record, installer or package-manager output, and resulting version.
- Relevant logs and monitoring evidence, test results, exceptions, compensating controls, and rollback decisions.
Related TechGeeks Resources
Authoritative References
Correction policy: If the authority changes affected versions, fixed versions, severity, exploitation information, mitigations, or required action, TechGeeks will update this notice and its verification date.
