Vulnerability · Published Aug 18, 2026 · Assigned by GitHub_M

CVE-2026-54730authentik: Authentication Flow Bypass via Unguarded challenge_valid() in AuthenticatorEndpointGDTCStage and GoogleChromeStageView

High 8.6

In plain English

A high-severity improper access control in authentik from goauthentik. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 53% of all known vulnerabilities).

Severity (CVSS 4.0)8.6High
Exploit odds (30 days)0.7%top 47.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

authentik is an open-source identity provider. Prior to 2026.2.6 and 2026.5.5, the enterprise Google Chrome device-trust stages advance the flow without confirming that the out-of-band device attestation actually ran. Affected enterprise deployments place either a Google Chrome Endpoint stage with mode set to REQUIRED or the deprecated Google Chrome Device Trust Connector stage in an authentication flow. The device attestation occurs in a verification iframe that calls the Google Verified Access API and records the verified device on success, but the vulnerable stages treat the flow as passed as soon as the stage is submitted. An attacker who can reach such a stage, including after primary username and password authentication, can skip the verification iframe and authenticate from a device that was never verified. Where device trust is the only additional factor, that protection is fully bypassed, while other configured factors remain in force. This issue is fixed in versions 2026.2.6 and 2026.5.5.

Affected products (as reported)

VendorProductVersions
goauthentik authentik < 2026.2.6>= 2026.5.0, < 2026.5.5

Weakness: CWE-284, CWE-807 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

References