CVE-2026-126129Auth0 ASP.NET Core Authentication improper authentication
CVE-2026-126129 is a improper authentication in Auth0 ASP.NET Core Authentication, not yet scored.
Why this priority: Not scored yet, and no exploitation signal.
Published · Updated · NVD status: Received
What it is
The software does not prove who a caller is, so an attacker can pass as someone else. A security check relies on a value the attacker can set.
How it is reached
The record does not say yet how the flaw is reached; the description below is the best guide until it is scored.
What an attacker gains
Its impact has not been scored yet. In practice, this kind of flaw lets an attacker act as a signed-in user, or an administrator, without valid credentials.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- Upgrade Auth0 ASP.NET Core Authentication to 1.12.0 or later.
Description from NVD
The Auth0 ASP.NET Core Authentication SDK incorrectly determines a session's OIDC Back-Channel Logout status, which may result in a logged-out session being accepted for access to protected endpoints.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Sign-in, session and token handling. The flaw sits between anonymous callers and authenticated sessions.
- Identity providers and SSO. The flaw sits between anonymous callers and authenticated sessions.
- Permission checks in APIs and admin surfaces. The flaw sits between one role or tenant and another.
- Multi-tenant services. The flaw sits between one role or tenant and another.
Trust boundaries in play
- Between anonymous callers and authenticated sessions. An attacker who crosses it can act as a signed-in user, or an administrator, without valid credentials.
- Between one role or tenant and another. An attacker who crosses it can reach data or actions their role should not allow.
Questions to answer about your own systems
- Where does Auth0 ASP.NET Core Authentication run in your systems, and at which version?
- Which of those instances are reachable by people you do not trust?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.