CVE-2026-19349

Lemonldap::NG::Portal versions from 2.0.0 before 2.16.9, from 2.17.0 before 2.21.5, from 2.22.0 before 2.23.3 for Perl allow authentication bypass via an OAuth2 state parameter stored as an SSO session in the GitHub and LinkedIn backends. Before redirecting to the identity provider, extractFormInfo() creates the state session with the positional call `getApacheSession( undef, 1, 0, 'GitHubState' )`. getApacheSession() takes a session id followed by a named argument hash, so the trailing arguments become that hash, `kind` defaults to SSO, and the state is written to the global session storage as a regular SSO session. Its identifier is handed to the unauthenticated visitor as the state parameter of the redirection URL. Any visitor who reaches the GitHub or LinkedIn endpoint can replay that identifier as a session cookie and obtain a valid SSO session without authenticating. The session holds neither _user nor authenticationLevel, which the shipped bootstrap configuration accepts because it grants virtual hosts a "default => accept" access rule; deployments whose rules test the user or require an authentication level are less exposed. Only configurations with the GitHub or LinkedIn authentication module enabled are affected.
https://nvd.nist.gov/vuln/detail/CVE-2026-19349

Categories

CWE-305 : Authentication Bypass by Primary Weakness
The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error. The provided password is only compared against the first character of the real password. The password is not properly checked, which allows remote attackers to bypass access controls by sending a 1-byte password that matches the first character of the real password. Chain: Forum software does not properly initialize an array, which inadvertently sets the password to a single character, allowing remote attackers to easily guess the password and gain administrative privileges.

References

 

AFFECTED (from MITRE)

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Vendor	Product	Versions
N/A	N/A	2.0.0 < 2.16.9 [affected] 2.17.0 < 2.21.5 [affected] 2.22.0 < 2.23.3 [affected]
© 2022 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.

CPE

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REMEDIATION

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EXPLOITS

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Exploit-db.com

id	description	date
No known exploits

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POC Github

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Other Nist (github, ...)

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CAPEC

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Common Attack Pattern Enumerations and Classifications

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