# CVE-2026-123804: SuperTokens Core: A session created concurrently with account unlink survives the unlink


- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 9 Nov 2026
- **Updated:** 9 Nov 2026
- **Also known as:** GHSA-2pc4-vw9j-454c

## What is CVE-2026-123804?

CVE-2026-123804 is a medium-severity vulnerability in supertokens-core, published on 9 Nov 2026. 

### Official description

SuperTokens Core is an open source authentication server. From 7.0.0 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, createNewSession can resolve a primary user before unlinkAccounts detaches a login method and then insert the session after unlink has enumerated and revoked the existing sessions. A user who controls the linked login method can exploit this race to retain a signed, database-backed, refreshable session as the former primary identity after that method is unlinked; the session persists until expiry or explicit revocation. 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.

Weakness: CWE-613 (DEPRECATED: Insufficient Session Expiration), CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-123804?


## How do I fix CVE-2026-123804?

No fix has been published for CVE-2026-123804 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-123804 being exploited?

There is no known exploitation of CVE-2026-123804 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-123804 and fix it if it is affected.

What it is: CVE-2026-123804 is a medium-severity vulnerability in supertokens-core, published on 9 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-123804 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-2026-123804/ (Markdown: https://insights.sbomify.com/CVE-2026-123804/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-123804
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123804
- OSV: https://osv.dev/vulnerability/CVE-2026-123804

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-123804/
Summaries are generated and may contain mistakes; the official description above is the record.