CVE-2026-123798supertokens supertokens-core improper authentication
CVE-2026-123798 is a improper authentication in supertokens supertokens-core, rated high (8.1 on CVSS 3.1).
Why this priority: High severity, with no exploitation signal yet.
Published · Updated · NVD status: Received
What it is
The software does not prove who a caller is, so an attacker can pass as someone else. A cryptographic signature is not checked properly, so forged data is accepted.
How it is reached
An attacker can exploit it over the network, with an ordinary user account, and nobody has to click anything.
What an attacker gains
A successful attack can read the data it protects and change data or behaviour. In practice, this kind of flaw lets an attacker act as a signed-in user, or an administrator, without valid credentials.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- Upgrade supertokens supertokens-core to a fixed version for your release line (12.0.10, 11.4.7, 11.3.7).
- Until it is patched, review who holds accounts that can reach it.
Description from NVD
SuperTokens Core is an open source authentication server. From 11.3.0 until 11.3.7, 11.4.7, and 12.0.10, SAML.verifySamlResponseSignature calls OpenSAML SignatureValidator.validate without first applying SAMLSignatureProfileValidator. The Core can therefore accept a cryptographically valid signature that references a different XML element from the Response or Assertion whose NameID and attributes are used for authentication. An ordinary user of the configured identity provider can move a genuinely signed element elsewhere in the document while supplying an attacker-authored identity-bearing element, causing XML Signature Wrapping authentication as another IdP user. Both response-level and assertion-level signing paths are affected, and SP-initiated login remains reachable without enabling allowIDPInitiatedLogin. This issue is fixed in versions 11.3.7, 11.4.7, and 12.0.10.
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
- Sign-in, session and token handling. The flaw sits between anonymous callers and authenticated sessions.
- Identity providers and SSO. The flaw sits between anonymous callers and authenticated sessions.
- TLS termination and service-to-service channels. The flaw sits on the network path between clients and services.
- Signature checks. The flaw sits on the network path between clients and services.
Trust boundaries in play
- Authenticated network access. An account is needed, so exposure follows who can sign in: customers, partners or staff.
- Between anonymous callers and authenticated sessions. An attacker who crosses it can act as a signed-in user, or an administrator, without valid credentials.
- On the network path between clients and services. An attacker who crosses it can read or tamper with traffic, or pass a forged message as genuine.
Questions to answer about your own systems
- Where does supertokens supertokens-core 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?
Read more
Patches and commits
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.