CVE-2026-92289Network attack vectorHinoki check available

Token theft via public-client PKCE bypass

Published Sep 25, 2026 · Updated Sep 25, 2026

PKCE bypass in Lemonldap::NG::Portal 2.23.0 through 2.23.3 allows remote attackers to exchange intercepted authorization codes for tokens. In PKCE-or-secret mode, checkEndPointAuthenticationCredentials skips secret comparison for public clients, so arbitrary Basic or form credentials satisfy the secret branch while validatePKCEChallenge accepts an absent challenge and verifier. Exploitation requires interception of a public client's authorization code and exposes the user's access, ID, and refresh tokens; dynamically registered clients use this mode.

CVSS severityUnavailable
Unscored
EPSS probability0.39%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

PKCE bypass in Lemonldap::NG::Portal 2.23.0 through 2.23.3 allows remote attackers to exchange intercepted authorization codes for tokens. In PKCE-or-secret mode, checkEndPointAuthenticationCredentials skips secret comparison for public clients, so arbitrary Basic or form credentials satisfy the secret branch while validatePKCEChallenge accepts an absent challenge and verifier. Exploitation requires interception of a public client's authorization code and exposes the user's access, ID, and refresh tokens; dynamically registered clients use this mode.

The record

CVE
CVE-2026-92289
Published
Sep 25, 2026
Updated
Sep 25, 2026
Vendor
LemonLDAP::NG
Product
Lemonldap::NG::Portal
Classifications
T1528
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.23.0 <2.23.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

LemonLDAP::NG · Lemonldap::NG::Portalversion=2.23.0 <2.23.4

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1528Steal Application Access Token

Public exploit references

No public exploit references are available in this record.

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Technologies

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