Is CVE-2026-123803 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-123803 being exploited in the wild.

How severe is CVE-2026-123803?

High severity, with a CVSS score of 8.1, published 9 November 2026.

Which products and versions are affected?

Supertokens Core 10.1.0 to 11.0.8, 11.1.0 to 11.1.3, 11.2.0 to 11.2.3, 11.3.0 to 11.3.7, 11.4.0 to 11.4.7, 12.0.0 to 12.0.10, 12.1.0 to 12.1.1, 12.2.0, 12.3.0.

Is there a fix for CVE-2026-123803?

Yes: fixed in 11.0.9, 11.1.4, 11.2.4, 11.3.8, 11.4.8, 12.0.11, 12.1.2, 12.2.1, 12.3.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-123803 attacked?

It is attacked over the network, in a hosted service.

Am I affected by CVE-2026-123803?

Check whether you run Supertokens Core at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-123803: SuperTokens Core cross-tenant WebAuthn authentication bypass

CVE-2026-123803 · Severity: high · CVSS 8.1 · Published 2026-11-09

SuperTokens Core is an open-source authentication server that manages user sign-in across multiple tenants. In multi-tenant deployments using WebAuthn (passkeys), a user with valid credentials in one tenant can sign in to a different tenant without membership, gaining unauthorized access. This allows account takeover and unauthorized data access across tenant boundaries.

Technologies: Supertokens Core. Vendors: Supertokens.

Quick answers

Is CVE-2026-123803 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-123803 being exploited in the wild.
How severe is CVE-2026-123803?: High severity, with a CVSS score of 8.1, published 9 November 2026.
Which products and versions are affected?: Supertokens Core 10.1.0 to 11.0.8, 11.1.0 to 11.1.3, 11.2.0 to 11.2.3, 11.3.0 to 11.3.7, 11.4.0 to 11.4.7, 12.0.0 to 12.0.10, 12.1.0 to 12.1.1, 12.2.0, 12.3.0.
Is there a fix for CVE-2026-123803?: Yes: fixed in 11.0.9, 11.1.4, 11.2.4, 11.3.8, 11.4.8, 12.0.11, 12.1.2, 12.2.1, 12.3.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-123803 attacked?: It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-123803?: Check whether you run Supertokens Core at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 11.0.9, 11.1.4, 11.2.4, 11.3.8, 11.4.8, 12.0.11, 12.1.2, 12.2.1, 12.3.1

Technical details

The vulnerability stems from insufficient tenant scoping in WebAuthn credential lookups: loadOptionsById_Transaction and getUserInfoByCredentialId_Transaction perform application-scoped passkey lookups without constraining results to the requested tenant, and WebAuthN.signIn does not verify the credential owner is a member of the target tenant. An attacker with a valid passkey in one tenant can submit its assertion to another tenant's sign-in endpoint in the same application and be authenticated there. The fix adds tenant scoping to credential queries and membership verification in the sign-in flow.

Affected products

SuperTokens SuperTokens Core 10.1.0 to 11.0.8, 11.1.0 to 11.1.3, 11.2.0 to 11.2.3, 11.3.0 to 11.3.7, 11.4.0 to 11.4.7, 12.0.0 to 12.0.10, 12.1.0 to 12.1.1, 12.2.0, 12.3.0

Timeline

2026-11-09: disclosed
2026-10-06: patched

References

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