authentik CVE-2026-72534

The attacker must possess a valid source-scoped SCIM provisioning token for the target authentik instance - a low-privilege credential (PR:L per CVSS vector) typically issued to directory synchronization services rather than end users. The SCIM provisioning feature must be enabled and at least one SCIM source must be configured in the authentik instance; default installations without SCIM sources are not vulnerable through this path. The attacker must know or be able to enumerate the exact display name of an existing administrator group; SCIM APIs commonly expose group listings that may permit name discovery without elevated privileges, lowering the effective barrier. No user interaction is required (UI:N) and the exploit executes entirely over the network (AV:N). Exploitation is bounded by: possession of a SCIM token (not freely obtainable without some level of prior access or compromise), and the requirement that the SCIM feature be actively configured - non-default in minimal deployments.

The official CVSS 3.1 vector AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score 8.8) accurately captures network-reachable, low-complexity exploitation requiring only a legitimately obtained SCIM provisioning token - the kind of credential routinely issued to directory sync services - and even a mid-sized municipal IT team in malbork running a self-hosted authentik instance should treat this as urgent given that successful exploitation yields complete IdP takeover and permanent administrator lockout with no recovery path short of direct database intervention. No EPSS score was available in the provided intelligence, and the vulnerability is not currently in the CISA KEV catalog, meaning confirmed active exploitation has not been documented; however, the absence of KEV should not be treated as a deprioritization signal given the conceptual simplicity of the attack. The scope metric S:U may materially understate real-world risk: authentik functions as a trust anchor for all downstream applications, so attacker control of the IdP cascades to every integrated service - an impact profile more consistent with S:C in practical terms. No POC has been identified at time of analysis, but the attack requires only a standard HTTP client and knowledge of an administrator group display name.

An attacker who has obtained a SCIM provisioning token - through credential theft, a compromised integration service account, or insider access - sends a crafted SCIM group creation or update request to the authentik SCIM endpoint with a group display name matching a known administrator group such as 'authentik Admins'. The SCIM ingest function matches on name, adopts the existing admin group, and replaces its membership with accounts controlled by the attacker, simultaneously removing all legitimate administrators and elevating the attacker to full IdP superuser. No public exploit code has been identified at time of analysis, but the attack requires no specialized tooling beyond a standard HTTP client capable of sending authenticated REST API requests.