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Fencer Vulns
medium 4.3

CVE-2026-12804 json

lemonldap-ng SAML Common Domain Cookie Endpoint CDC.pm redirect

published 2026-06-21 4 mo ago modified 2026-06-22 4 mo ago also EUVD-2026-38190

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

A vulnerability was detected in lemonldap-ng up to 2.23.0. Impacted is an unknown function in the library lemonldap-ng-portal/lib/Lemonldap/NG/Portal/CDC.pm of the component SAML Common Domain Cookie Endpoint. Performing a manipulation of the argument url results in open redirect. The attack is possible to be carried out remotely. The exploit is now public and may be used. Applying a patch is the recommended action to fix this issue. The vendor confirms, that "it has been fixed some days ago and will be available in 2.23.1. CDC is quite never used, so the impact is very low."

Patch / fix

  • lemonldap-ng Debian 12 2.16.1+ds-deb12u9
  • lemonldap-ng Debian 13 2.21.2+ds-1+deb13u3
  • lemonldap-ng Debian 14 2.23.1+ds-1

debian advisories DEBIAN-CVE-2026-12804

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-12804 updated cvss 4.3

lemonldap-ng: Lemonldap-NG: Open Redirect via URL manipulation in SAML Common Domain Cookie Endpoint

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C
CNA 3.0 4.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C
CNA 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N/E:POC/RL:OF/RC:C
CNA 4.0 2.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
CNA 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Affected products

  • n/a lemonldap-ng

Classification

Weakness
  • CWE-601 URL Redirection to Untrusted Site

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.