Is CVE-2026-123801 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-123801 being exploited in the wild.

How severe is CVE-2026-123801?

High severity, with a CVSS score of 7.4, published 9 November 2026.

Which products and versions are affected?

Supertokens Core 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, and 12.3.0.

Is there a fix for CVE-2026-123801?

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

How is CVE-2026-123801 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-123801?

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-2026-123801: SuperTokens Core SAML replay protection bypass in callback

CVE-2026-123801 · Severity: high · CVSS 7.4 · Published 2026-11-09

SuperTokens Core is an open-source authentication server used to manage user logins across applications. The SAML callback handler fails to properly validate SAML assertions, allowing attackers to replay legitimate SAML responses or forge authentication for different identities. An attacker could bypass login requirements or take over user accounts by replaying or modifying captured SAML assertions.

Technologies: Supertokens Core. Vendors: Supertokens.

Quick answers

Is CVE-2026-123801 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-123801 being exploited in the wild.
How severe is CVE-2026-123801?: High severity, with a CVSS score of 7.4, published 9 November 2026.
Which products and versions are affected?: Supertokens Core 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, and 12.3.0.
Is there a fix for CVE-2026-123801?: Yes: fixed in 11.3.8, 11.4.8, 12.0.11, 12.1.2, 12.2.1, and 12.3.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-123801 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-123801?: 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: 11.3.8, 11.4.8, 12.0.11, 12.1.2, 12.2.1, and 12.3.1

Technical details

The SAML.handleCallback function in SuperTokens Core does not consume RelayState on resubmission, record assertion identifiers, validate Response.InResponseTo binding, or enforce Destination and SubjectConfirmationData validation. This permits SAML assertion replay attacks in SP-initiated flows (by resubmitting a valid assertion with its matching RelayState before NotOnOrAfter expiry) and in IdP-initiated flows (without RelayState). Missing Response.InResponseTo checks allow attackers to complete in-progress logins with assertions for different identities, and the callback generates independently redeemable authorization codes for each accepted assertion.

Affected products

SuperTokens SuperTokens Core 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, and 12.3.0

Timeline

2026-11-09: disclosed

References

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