CVE-2026-46623: OpenAM Account Takeover via Unverified Password Change in OAuth2 Module

Description

An Unverified Password Change (CWE-620) and Use of Weak Credentials (CWE-1391) issue in OpenAM’s OAuth2 authentication module silently rewrites a local user’s password to the literal string of their username on OAuth2 re-login of an existing account. The default ldapService chain then accepts the username as the password for that user, allowing an unauthenticated attacker to obtain a session via the standard authenticate endpoint with both username and password set to the username, without any IdP interaction. This affects OpenAM Community Edition through version 16.0.6 and was patched in version 16.1.1.