CVE-2026-54730 — authentik: Authentication Flow Bypass via Unguarded challenge_valid() in AuthenticatorEndpointGDTCStage and GoogleChromeStageView
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.7% (30-day exploitation probability)+8
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Goauthentik Authentik).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Goauthentik | Authentik | version < 2026.2.6version >= 2026.5.0, < 2026.5.5 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.6 | CVSS 4.0 | High | — | — | security-advisories@github.com via NIST National Vulnerability Database |
| 8.6 | CVSS 4.0 | High | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Audit administrative actions and access to resources outside each user’s normal pattern.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · goauthentik/authentik
- SSVC assessment updated
- Record published
- CVSS changed · 8.6
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
7 on the record
- github.com/goauthentik/authentik/pull/24053
- github.com/goauthentik/authentik/security/advisories/GHSA-3v9h-3hrm-29cx
- github.com/goauthentik/authentik/commit/27866a94f29d0d7f784b3c462a697a968d3f6b9c
- github.com/goauthentik/authentik/releases/tag/version/2026.5.5
- github.com/goauthentik/authentik/releases/tag/version/2026.2.6
- github.com/goauthentik/authentik/pull/24058
- github.com/goauthentik/authentik/commit/85adb0bbbd7ad4f2807ec21cf25bb42aee81afbc
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-94613 authentik: Denial of Service via Document Type Declarations in SAML Messages 21d
- High CVE-2026-94611 authentik: Stored credentials are readable with view permission alone 21d
- High CVE-2026-94609 authentik: Privilege Escalation to Superuser via Group Hierarchy 21d
- High CVE-2026-94606 authentik: MFA Bypass via State Confusion / Parameter Injection in AuthenticatorEmailStage 21d
- High CVE-2026-94612 authentik: Authentication bypass via assertion confusion in SAML sources 21d
- Medium CVE-2026-55106 authentik: Unauthenticated LDAP directory data disclosure Aug 18, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-54730 is "authentik: Authentication Flow Bypass via Unguarded challenge_valid() in AuthenticatorEndpointGDTCStage and GoogleChromeStageView", rated High. It affects Authentik (Goauthentik); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.6 describes technical severity. EPSS 0.68% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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