What is CVE-2026-123803?

CVE-2026-123803 is a high-severity vulnerability in Supertokens Supertokens-Core, classified under Incorrect Authorization. CVSS score: 8.1/10. Published 2026-11-09.

How severe is CVE-2026-123803?

High severity. CVSS v3 base score is 8.1 out of 10.

Auth bypass in Supertokens Supertokens-Core

CVE-2026-123803

SuperTokens Core is an open source authentication server. From 10.1.0 until 11.0.9, 11.1.4, 11.2.4, 11.3.8, 11.4.8, 12.0.11, 12.1.2, 12.2.1, and 12.3.1, loadOptionsById_Transaction and getUserInfoByCredentialId_Transaction perform application-scoped WebAuthn lookups without constraining them to the requested tenant, and WebAuthN.signIn does not verify tenant membership. In a multi-tenant deployment using WebAuthn with a shared user pool, an ordinary user who possesses their own valid passkey in one tenant can submit its assertion to another tenant's sign-in endpoint in the same application and be authenticated there despite having no membership in the target tenant. This issue is fixed in versions 11.0.9, 11.1.4, 11.2.4, 11.3.8, 11.4.8, 12.0.11, 12.1.2, 12.2.1, and 12.3.1.

Vulnerability class: Broken Access Control

Published 2026-11-09 · last modified 2026-11-09.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Supertokens Supertokens-Core — versions >= 10.1.0, < 11.0.0, >= 11.0.0, < 11.0.9, >= 11.1.0, < 11.1.4

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-123803?: CVE-2026-123803 is a high-severity vulnerability in Supertokens Supertokens-Core, classified under Incorrect Authorization. CVSS score: 8.1/10. Published 2026-11-09.
How severe is CVE-2026-123803?: High severity. CVSS v3 base score is 8.1 out of 10.