What is CVE-2019-15941?

CVE-2019-15941 is a critical-severity vulnerability in Lemonldap-Ng Lemonldap\, classified under Incorrect Authorization. CVSS score: 9.8/10. Published 2019-09-25.

How severe is CVE-2019-15941?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Auth bypass in Lemonldap-Ng Lemonldap\

CVE-2019-15941

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.

Vulnerability class: Broken Access Control

Published 2019-09-25 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.025 (83.8th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 84th percentile — 83.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.022 · newest: 0.025 · change: +0.003

Affected products

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

gitlab.ow2.org/lemonldap-ng/lemonldap-ng/issues/1881 (Third Party Advisory)
projects.ow2.org/view/lemonldap-ng/lemonldap-ng-2-0-6-is-out/ (Third Party Advisory)
www.debian.org/security/2019/dsa-4533 (vendor-advisory, Third Party Advisory)
seclists.org/bugtraq/2019/Sep/46 (mailing-list, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2019-15941?: CVE-2019-15941 is a critical-severity vulnerability in Lemonldap-Ng Lemonldap\, classified under Incorrect Authorization. CVSS score: 9.8/10. Published 2019-09-25.
How severe is CVE-2019-15941?: Critical severity. CVSS v3 base score is 9.8 out of 10.