CVE-2026-21854
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe Tarkov Data Manager is a tool to manage the Tarkov item data. Prior to 02 January 2025, an authentication bypass vulnerability in the login endpoint allows any unauthenticated user to gain full admin access to the Tarkov Data Manager admin panel by exploiting a JavaScript prototype property access vulnerability, combined with loose equality type coercion. A series of fix commits on 02 January 2025 fixed this and other vulnerabilities.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceAuthentication bypass in Tarkov Data Manager's login endpoint exploiting JavaScript prototype property access (prototype pollution) combined with loose equality type coercion, allowing unauthenticated users to gain full admin panel access.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 2025-01-02CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed version of Tarkov Data ManagerLocate the application directory and check the version file, package.json, or build metadata. Common paths include the application root directory or installation folder. Run a command to display the version if a CLI tool exists, such as 'tdm --version' or check the about panel in the admin interface.Affected if The installed version is any version released before 02 January 2025 (versions < 2025-01-02).
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Verify login endpoint accessibilityCheck if the /login or equivalent authentication endpoint responds without requiring credentials. Use a tool like curl or browser DevTools to send a GET request to the login endpoint and observe the response status code.Affected if The endpoint returns a 200 OK status without any authentication token or session cookie present in the request.
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Inspect authentication code for loose equality operatorsExamine the source code of the authentication module (typically found in files named auth.js, login.js, middleware/auth.js, or similar). Search for instances of the double equals operator (==) used in conditional checks related to user validation, role verification, or session handling.Affected if Code contains '==' operators used in authentication or privilege checks, enabling type coercion exploitation.
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Check for prototype pollution input handlingReview input validation logic in the login endpoint and any API routes. Look for code that directly assigns or merges user-supplied JSON input into objects without sanitizing property names like '__proto__' or 'constructor'.Affected if User input is directly assigned to objects without filtering out prototype-related property names (__proto__, constructor).
You are affected if Tarkov Data Manager version is before 2025-01-02 AND the application uses loose equality (==) in authentication logic AND accepts user input that can manipulate object prototype properties.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped2025-01-02
Update to the patched version released 02 January 2025 or later; implement strict equality checks (===) and sanitize/validate all user inputs to prevent prototype pollution.
Any version released on or after 2025-01-02 (check releases after the fix commits)
- 1. Navigate to the Tarkov Data Manager GitHub repository at github.com/the-hideout/tarkov-data-manager
- 2. Check the releases page to identify the latest version released on or after January 2, 2025
- 3. Download or pull the fixed release version
- 4. Deploy the updated version to replace the vulnerable installation
- 5. Verify that the authentication bypass is no longer exploitable by testing the login endpoint
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-21854 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-21854 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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