# CVE-2026-123801: SuperTokens Core is an open source authentication server.


- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 9 Nov 2026
- **Updated:** 10 Nov 2026
- **Also known as:** GHSA-3r7x-rhvc-fw28

## What is CVE-2026-123801?

CVE-2026-123801 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 11.3.8, 11.4.8, 12.0.11, 12.1.2, 12.2.1, and 12.3.1, SAML.handleCallback does not consume RelayState, record assertion identifiers, or enforce Response.InResponseTo. In the SP-initiated flow, an attacker who obtains a legitimately issued, still-valid SAML response and its matching RelayState can resubmit the pair to /recipe/saml/callback before the assertion's NotOnOrAfter time; in the IdP-initiated flow, the assertion can be replayed without RelayState. The missing Response.InResponseTo check also permits an in-progress login to be completed with an assertion for a different identity and fails to enforce allowIDPInitiatedLogin=false. The callback does not validate Destination or SubjectConfirmationData Recipient and NotOnOrAfter, and each accepted callback mints a fresh, independently redeemable authorization code carrying the captured user's identity. This issue is fixed in versions 11.3.8, 11.4.8, 12.0.11, 12.1.2, 12.2.1, and 12.3.1.

Weakness: CWE-384 (Session Fixation), CWE-346 (Origin Validation Error), CWE-294 (Authentication Bypass by Capture-replay)

## Which versions are affected by CVE-2026-123801?


## How do I fix CVE-2026-123801?

No fix has been published for CVE-2026-123801 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-123801 being exploited?

There is no known exploitation of CVE-2026-123801 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-123801 and fix it if it is affected.

What it is: CVE-2026-123801 is a high-severity vulnerability in supertokens-core, published on 9 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-123801 in the wild and no public exploit code.

Affected product: supertokens-core. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-123801/ (Markdown: https://insights.sbomify.com/CVE-2026-123801/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-123801
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123801
- OSV: https://osv.dev/vulnerability/CVE-2026-123801

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-123801/
Summaries are generated and may contain mistakes; the official description above is the record.