CVE-2026-126389n8n-io n8n authentication bypass by alternate path
CVE-2026-126389 is a authentication bypass by alternate path in n8n-io n8n, rated medium (6.3 on CVSS 4.0).
Why this priority: Medium severity, with no exploitation signal.
Published · Updated · NVD status: Deferred
What it is
A second route to a protected function skips the sign-in check.
How it is reached
An attacker can exploit it over the network, without an account, and nobody has to click anything. Success also depends on conditions the attacker does not fully control.
What an attacker gains
The direct impact is limited: partial access to data or a partial outage. In practice, this kind of flaw lets an attacker act as a signed-in user, or an administrator, without valid credentials. The damage can spread past the vulnerable component into others.
Is it being exploited?
There is no public report of exploitation yet. EPSS estimates a 0.35% chance of exploitation activity in the next 30 days, higher than 29% of scored CVEs.
What to do
- Upgrade n8n-io n8n to a fixed version for your release line (1.123.89, 2.46.1, 2.45.5).
- Until it is patched, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
Description from NVD
n8n before 1.123.89 contains an authentication bypass vulnerability in the Chat Trigger that allows unauthenticated attackers to skip n8n User Auth through the setup GET webhook route in embedded chat mode. Attackers can send unauthenticated GET requests to the chat webhook URL to read named session conversation history or trigger workflows with attacker-supplied input.
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.
Trust boundaries in play
- Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
- Isolation between components. The impact crosses out of the vulnerable component into others it should be isolated from.
- Between anonymous callers and authenticated sessions. An attacker who crosses it can act as a signed-in user, or an administrator, without valid credentials.
Questions to answer about your own systems
- Where does n8n-io n8n run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- 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.