CVE-2026-63183omniauth origin validation error
CVE-2026-63183 is a origin validation error in omniauth, rated medium (6.9 on CVSS 4.0).
Why this priority: Medium severity, with no exploitation signal.
Published · Updated · NVD status: Received
What it is
The software does not check where a request or message really comes from.
How it is reached
An attacker can exploit it over the network, without an account, and nobody has to click anything.
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 inside a signed-in user's browser session. 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 0.18% chance of exploitation activity in the next 30 days, higher than 8% of scored CVEs.
What to do
- Upgrade omniauth to 2.2.0 or later.
- Until it is patched, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
Description from NVD
OmniAuth is a flexible authentication system utilizing Rack middleware. Prior to 2.2.0, OmniAuth derives provider callback URLs from request-controlled host information when neither a fixed full_host nor framework-level incoming host validation is configured. A remote unauthenticated client can supply a forged Host header, creating a host header injection risk in applications whose web framework does not verify incoming host headers. Applications using appropriately configured Rails host authorization or a fixed full_host are not affected by this path. This issue is fixed in version 2.2.0.
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
- Web front ends and single-page apps. The flaw sits between a user's browser and the web application.
- Admin consoles served to a browser. The flaw sits between a user's browser and the web application.
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 a user's browser and the web application. An attacker who crosses it can act inside a signed-in user's browser session.
Questions to answer about your own systems
- Where does omniauth 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.