CVE-2026-116239 in pgAdmin
Summary
by MITRE • 10/30/2026
In server mode pgAdmin 4 keeps an account per authentication source, so the same username can exist as, for example, an internal account and an LDAP account. After LDAP or Kerberos authenticated a user, pgAdmin chose the account to log in by username alone, or took the account Flask-Security's login form had looked up, without checking that it came from the source that authenticated the user. The session therefore belonged to another account, with its role, its servers and its saved database passwords:
- An LDAP or Kerberos user whose username matched an internal account was logged in as that internal account, including the administrator account created when pgAdmin is first set up. - With internal authentication listed before LDAP or Kerberos in AUTHENTICATION_SOURCES, the login form's internal validation looks up the account whose email was typed and keeps it even though its password does not match. A Kerberos user could type another Kerberos user's principal and be logged in as that user, and an LDAP user could do the same with an LDAP account whose email is their username.
Exploitation requires valid credentials for an LDAP directory or Kerberos realm that pgAdmin is configured to use.
The fix looks the account up by the authenticated username and the source that authenticated it, and no longer uses the account the login form found for any source but internal authentication. Internal authentication logs in that account only if it is an internal account. Desktop mode is not affected.
This issue affects pgAdmin 4: before 9.19.
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Analysis
by VulDB Data Team • 10/31/2026
The vulnerability identified in pgAdmin 4 prior to version 9.19 represents a critical identity resolution flaw within the server-mode authentication architecture, specifically affecting how user sessions are mapped to internal application accounts after external directory services such as LDAP or Kerberos have successfully authenticated a principal. In environments where multiple authentication sources are configured simultaneously, pgAdmin maintains distinct account records for each source, meaning that an identical username can exist independently as both an internal database record and an entry within an external identity provider like Active Directory via LDAP or a Kerberos realm. The core technical deficiency lies in the post-authentication logic which fails to bind the authenticated session strictly to the specific authentication source that validated the credentials. Instead of verifying that the account being logged into corresponds exactly to the entity that was just authenticated, the system relies on username matching alone or accepts an account lookup performed by Flask-Security during the initial login form submission without validating its origin against the successful external authentication event. This disconnect allows for a severe identity confusion attack where the application session is attached to an arbitrary internal account rather than the intended user profile from the directory service, leading to potential privilege escalation and unauthorized access to sensitive configuration data.
The operational impact of this flaw is significant because it enables attackers with valid credentials in any configured external authentication source to impersonate other users within the pgAdmin interface, including high-privilege administrative accounts. For instance, if an LDAP user possesses a username that matches an existing internal account, such as the default administrator created during initial setup, the system will log them into that powerful internal profile rather than creating or logging them into their correct external-based session. This grants the attacker full administrative control over the database management interface, including access to all registered servers and saved database passwords stored within pgAdmin. Furthermore, when internal authentication is prioritized in the AUTHENTICATION_SOURCES configuration list, a different vector emerges where an attacker can exploit the pre-validation logic of the login form. By entering another user's principal or email address into the username field while authenticating via Kerberos or LDAP, the system may retain the internally looked-up account even if its password does not match the external credentials provided. This allows a valid Kerberos user to log in as any other Kerberos user whose principal is known, and similarly for LDAP users, effectively bypassing authentication controls through identity spoofing rather than credential cracking.
From a classification perspective, this vulnerability aligns with CWE-287 Improper Authentication, specifically the failure to verify that the authenticated entity matches the intended account context, as well as CWE-640 Weak Password Recovery Mechanism for Forgotten Password if exploited in conjunction with other flaws, though primarily it is an identity management error. In terms of MITRE ATT&CK mapping, this behavior facilitates Account Manipulation and Privilege Escalation techniques where an adversary leverages valid credentials to assume a higher privileged account or impersonate another user within the application layer. The exploitation requires that the attacker possesses legitimate credentials for either the LDAP directory or Kerberos realm configured in pgAdmin 4, making it particularly dangerous in enterprise environments where single sign-on is enabled but internal and external identities are not strictly segregated during session creation.
The remediation strategy implemented in version 9.19 addresses this by enforcing strict binding between the authentication source and the account lookup process. The updated logic ensures that after LDAP or Kerberos authentication succeeds, pgAdmin looks up the user account specifically using both the authenticated username and the identity of the source that performed the verification, thereby preventing cross-source impersonation. Additionally, for internal authentication sources, the system now restricts login to only those accounts explicitly defined as internal, ignoring any external lookups that might have occurred during form processing. This separation ensures that session ownership is correctly attributed based on the actual method of identity proofing rather than superficial username matches. Organizations running pgAdmin 4 in server mode must upgrade immediately to version 9.19 or later to mitigate this risk. Until patched, administrators should consider restricting access to internal authentication sources if possible and ensuring that usernames across LDAP/Kerberos directories do not overlap with critical internal administrative accounts to reduce the attack surface for identity confusion attacks.