# CVE-2026-123803: SuperTokens Core: WebAuthn sign-in accepts a passkey across tenant boundaries

Status: published. Published: 2026-11-09. Updated: 2026-11-09.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- supertokens / supertokens-core: >= 10.1.0, < 11.0.0 (affected); >= 11.0.0, < 11.0.9 (affected); >= 11.1.0, < 11.1.4 (affected); >= 11.2.0, < 11.2.4 (affected); >= 11.3.0, < 11.3.8 (affected); >= 11.4.0, < 11.4.8 (affected); >= 12.0.0, < 12.0.11 (affected); >= 12.1.0, < 12.1.2 (affected); >= 12.2.0, < 12.2.1 (affected); >= 12.3.0, < 12.3.1 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 3.1: 8.1 (high); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N; source: CNA: GitHub_M

- CVSS 3.1: 8.1 (high); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-863, CWE-1220

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/supertokens/supertokens-core/security/advisories/GHSA-6v34-w48w-44rc (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/supertokens/supertokens-core/commit/01ca34a06baa0d22db008f38c8eabd1f6695d9a6 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/commit/030643edea5d69e0009ceeecbc5dd70be5c66186 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/commit/1e3e4d9b25237a9c8fd77cbe0d4d0ecb360d8cd6 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/commit/84492e38f9eb6db0cc338674ce5e94d1603bef08 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/commit/982d420a5ac29d5e362eaf39169a7a9f5339abeb (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/commit/a3d033022effb00ccf0c4ec6ca77c36eb1a24617 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/commit/ad768c1925e245930e5fbf9441452d85564de91d (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/commit/b933b6c9b4495e47a8b3efeb5a70e9d014777320 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/commit/e19d173f47658d036685d3020e18819c5f3690b7 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/releases/tag/v11.0.9 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/releases/tag/v11.1.4 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/releases/tag/v11.2.4 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/releases/tag/v11.3.8 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/releases/tag/v12.0.11 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/releases/tag/v12.1.2 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/releases/tag/v12.2.1 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/releases/tag/v12.3.1 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/supertokens/supertokens-core/commit/01ca34a06baa0d22db008f38c8eabd1f6695d9a6 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/commit/030643edea5d69e0009ceeecbc5dd70be5c66186 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/commit/1e3e4d9b25237a9c8fd77cbe0d4d0ecb360d8cd6 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/commit/84492e38f9eb6db0cc338674ce5e94d1603bef08 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/commit/982d420a5ac29d5e362eaf39169a7a9f5339abeb (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/commit/a3d033022effb00ccf0c4ec6ca77c36eb1a24617 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/commit/ad768c1925e245930e5fbf9441452d85564de91d (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/commit/b933b6c9b4495e47a8b3efeb5a70e9d014777320 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/commit/e19d173f47658d036685d3020e18819c5f3690b7 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/releases/tag/v11.0.9 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/releases/tag/v11.1.4 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/releases/tag/v11.2.4 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/releases/tag/v11.3.8 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/releases/tag/v12.0.11 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/releases/tag/v12.1.2 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/releases/tag/v12.2.1 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/releases/tag/v12.3.1 (security-advisories@github.com)

- https://github.com/supertokens/supertokens-core/security/advisories/GHSA-6v34-w48w-44rc (security-advisories@github.com)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-123803; retrieved 2026-11-10; source updated 2026-11-09

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123803; retrieved 2026-11-10; source updated 2026-11-09

Revision: b8685f428100509e2ba432cec698193ea09d964ce0d3687b4426643df12ecfc4

Canonical: https://y2.dev/cve/CVE-2026-123803

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