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Vulnerabilities

Vulnerability · CVE-2026-92289

Lemonldap::NG::Portal versions from 2.23.0 before 2.23.4 for Perl allow a PKCE bypass for public Relying Parties in "PKCE or secret" mode because checkEndPointAuthenticationCredent

Published Sep 25, 2026 · catalog updated Oct 18, 2026 · Lemonldap::NG::Portal versions from 2.23.0

Check if you run it

No confirmed exploitation is on record for CVE-2026-92289. EPSS is 0.39%. Act only if a listed version of Lemonldap::NG::Portal versions from 2.23.0 is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Lemonldap::NG::Portal versions from 2.23.0).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical9.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.39%
Remediation
Advisory link
Affected products
Debian:13 lemonldap-ng · Debian:14 lemonldap-ng

Lemonldap::NG::Portal versions from 2.23.0 before 2.23.4 for Perl allow a PKCE bypass for public Relying Parties in "PKCE or secret" mode because checkEndPointAuthenticationCredentials does not verify the client secret. With oidcRPMetaDataOptionsRequirePKCE set to 2, the authorization endpoint issues a code even when the request carries no code_challenge, and token() admits the exchange as long as a challenge was stored or an authentication method was returned for the caller. checkEndPointAuthenticationCredentials() skips the secret comparison for a Relying Party marked public and still returns the method deduced from the request, so any Basic or form credential satisfies the secret branch. validatePKCEChallenge() then passes, because neither a challenge nor a verifier is present. An attacker who intercepts an authorization code issued to a public Relying Party can exchange it for the user's access, ID and refresh tokens by replaying the client_id with an arbitrary secret, which is the attack PKCE prevents. Dynamic client registration creates every Relying Party in this mode.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Debian:13 lemonldap-ng0 → 2.21.2+ds-1+deb13u4
  • Debian:14 lemonldap-ng0 → 2.23.4+ds-1

How to fix CVE-2026-92289

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-92289. EPSS is 0.39%. Act only if a listed version of Lemonldap::NG::Portal versions from 2.23.0 is installed.

Which versions are affected?

Compare what you have installed with 0 → 2.21.2+ds-1+deb13u4, 0 → 2.23.4+ds-1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.39%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Debian security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 25, 2026 · Trivy Vulnerability DB

    Detected

    Lemonldap::NG::Portal versions from 2.23.0 before 2.23.4 for Perl allow a PKCE bypass for public Relying Parties in "PKCE or secret" mode because checkEndPointAuthenticationCredentials does not verify the client secret. With oidcRPMetaDataOptionsRequirePKCE set to 2, the authorization endpoint issues a code even when the request carries no code_challenge, and token() admits the exchange as long as

  2. Oct 18, 2026 · Trivy Vulnerability DB

    Fix available

    lemonldap-ng fixed in 2.21.2+ds-1+deb13u4; lemonldap-ng fixed in 2.23.4+ds-1

  3. Oct 18, 2026 · Trivy Vulnerability DB

    Fix available

    lemonldap-ng fixed in 2.21.2+ds-1+deb13u4

  4. Oct 18, 2026 · Trivy Vulnerability DB

    Fix available

    lemonldap-ng fixed in 2.23.4+ds-1

  5. Oct 18, 2026 · Trivy Vulnerability DB

    Updated

    Lemonldap::NG::Portal versions from 2.23.0 before 2.23.4 for Perl allow a PKCE bypass for public Relying Parties in "PKCE or secret" mode because checkEndPointAuthenticationCredentials does not verify the client secret. With oidcRPMetaDataOptionsRequirePKCE set to 2, the authorization endpoint issues a code even when the request carries no code_challenge, and token() admits the exchange as long as

Sources

  • CVE.orgVulnerability recordCVE-2026-92289

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-92289

    30-day exploitation probability 0.4%

    first.org
  • OpenSSF OSV / OSV ScannerPackage advisoryDEBIAN-CVE-2026-92289
    osv.dev
  • Trivy Vulnerability DBPackage advisoryDEBIAN-CVE-2026-92289

    Lemonldap::NG::Portal versions from 2.23.0 before 2.23.4 for Perl allow a PKCE bypass for public Relying Parties in "PKCE or secret" mode because checkEndPointAuthenticationCredentials does not verify the client secret. With oidcRPMetaDataOptionsRequirePKCE set to 2, the authoriz

    osv.dev

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.