CVE-2026-54730

authentik: Authentication Flow Bypass via Unguarded challenge_valid() in AuthenticatorEndpointGDTCStage and GoogleChromeStageView

Published Aug 18, 2026 CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Goauthentik
Goauthentik authentik
Vendors & Products Goauthentik
Goauthentik authentik
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title authentik: Authentication Flow Bypass via Unguarded challenge_valid() in AuthenticatorEndpointGDTCStage and GoogleChromeStageView
Weaknesses CWE-284
CWE-807
References
Metrics cvssV4_0

{'score': 8.6, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 18, 2026, 5:21 PM
Reserved
Jun 15, 2026, 11:07 PM
Status
Deferred
Published
Aug 18, 2026, 5:16 PM
Modified
Oct 22, 2026, 10:10 PM