CVE-2026-100612 in Capgo
Summary
by MITRE • 09/26/2026
Capgo (capgo.app) through version 12.261.0 contains an incomplete access-control fix for the public.sso_providers table. Migration 20260826100000_sso_providers_block_direct_active_insert.sql installs a BEFORE UPDATE guard (enforce_sso_provider_client_update_guard()) that freezes only the dns_verified_at, domain, status and enforce_sso columns; provider_id (as well as metadata_url and attribute_mapping) is left writable. Because the table is granted ALL to the anon and authenticated roles with no column-level restriction, and PostgreSQL row-level security policies such as allow_org_admins_update_sso_providers constrain only which row may be updated and not which columns, a user holding the org_admin tier permission org.update_settings can PATCH provider_id over PostgREST to an identity provider under their control. Since provider_id is the trust anchor binding an email domain to an authorized IdP, the attacker can then authenticate through their own IdP while asserting the org owner's email; the server-side provider match succeeds and the merge routine attaches the attacker's SSO identity to the existing owner account, nulls its password, and deletes its other identities and sessions. This results in vertical privilege escalation from org_admin to org owner/super_admin, account takeover, and lockout of the legitimate owner. Exploitation requires that the target organization has an active SSO provider configured and that the attacker already holds org_admin in that organization. No patched version is available.
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Analysis
by VulDB Data Team • 09/26/2026
The vulnerability identified in Capgo versions through 12.261.0 represents a critical failure in access control mechanisms, specifically within the handling of Single Sign-On (SSO) provider configurations. The core issue stems from an incomplete remediation effort intended to secure the public.sso_providers table against unauthorized modifications. While a database migration script introduced a BEFORE UPDATE trigger designed to enforce strict immutability on certain sensitive fields such as dns_verified_at, domain, status, and enforce_sso, it failed to apply similar protections to other critical columns including provider_id, metadata_url, and attribute_mapping. This oversight creates a significant security gap because the table retains broad write permissions for both anon and authenticated roles without implementing granular column-level restrictions that would prevent modification of these specific fields regardless of user role or intent.
From an architectural perspective, this flaw exploits the limitations of PostgreSQL row-level security policies which typically govern access at the row level rather than the column level. The existing policy allow_org_admins_update_sso_providers restricts which rows can be updated based on organizational membership but does not constrain which columns within those rows are modifiable. Consequently, an attacker possessing the org.update_settings permission associated with the org_admin tier is able to execute PATCH requests via PostgREST that target and modify the provider_id field. This capability allows the attacker to overwrite the legitimate identity provider identifier with one under their own control, effectively hijacking the trust anchor that binds a specific email domain to an authorized authentication source.
The operational impact of this vulnerability is severe, leading directly to vertical privilege escalation from org_admin to org owner or super_admin status. By manipulating the provider_id, the attacker can configure the system to authenticate through an identity provider they control while asserting the email address of the organization's owner. When the server-side validation occurs, it recognizes the domain as valid and matches it against the manipulated SSO configuration. This triggers a merge routine that attaches the attacker's newly authenticated SSO identity to the existing owner account. Crucially, this process nullifies the legitimate password associated with the account and deletes other linked identities and active sessions, resulting in immediate account takeover and permanent lockout of the rightful administrator.
This attack vector aligns closely with CWE-269 Improper Privilege Management and CWE-732 Incorrect Permission Assignment for Critical Resource, as it involves exploiting insufficient access controls to gain elevated privileges on a critical system resource. In terms of the MITRE ATT&CK framework, this vulnerability facilitates Account Manipulation (T1098) by altering account properties to maintain persistent access, followed by Privilege Escalation (T1078) to assume higher-level roles within the organization. The exploitation requires specific preconditions including an active SSO provider configuration and existing org_admin privileges, but once achieved, it allows for complete compromise of organizational leadership accounts without requiring further authentication steps beyond standard web API interactions.
Mitigation strategies are currently limited by the absence of a patched version in official releases. Immediate defensive measures should focus on implementing manual database-level interventions to restrict column-level write access for non-administrative roles until an upstream fix is deployed. This includes revoking UPDATE permissions on specific columns like provider_id from the anon and authenticated roles at the PostgreSQL level, or modifying application logic to enforce stricter validation that prevents changes to trust anchor fields via API endpoints. Organizations should also monitor for unusual SSO configuration changes and ensure multi-factor authentication is enforced where possible to reduce reliance solely on password-based recovery mechanisms which are bypassed by this vulnerability.