CVE-2026-123798 SuperTokens Core: SAML XML Signature Wrapping authentication bypass — any IdP user can authenticate as any other user
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-123798?
CVE-2026-123798 is a high-severity vulnerability in supertokens-core, published on 9 Nov 2026.
Official description
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.
Which versions are affected by CVE-2026-123798?
How do I fix CVE-2026-123798?
No fix has been published for CVE-2026-123798 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-123798 being exploited?
There is no known exploitation of CVE-2026-123798 in the wild and no public exploit code.
Sources
Also known as GHSA-gvx2-mwmj-wwvj.