dbcve.org
Auth0 PhpApplication · Auth0

CVE-2026-34236

CRITICAL · 9.8 CVSS v3.1 Published 2026-04-01
Fix available
A fix is available. Upgrade to 8.19.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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 · unedited
Auth0-PHP is a PHP SDK for Auth0 Authentication and Management APIs. From version 8.0.0 to before version 8.19.0, in applications built with the Auth0 PHP SDK, cookies are encrypted with insufficient entropy, which may result in threat actors brute-forcing the encryption key and forging session cookies. This issue has been patched in version 8.19.0.

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 confidence

The Auth0-PHP SDK versions 8.0.0 through 8.19.0 use insufficient entropy when encrypting cookies, allowing threat actors to brute-force the encryption key and forge session cookies, potentially gaining unauthorized access to user sessions.

MitigationUpgrade the Auth0-PHP SDK to version 8.19.0 or later to obtain the patched encryption with proper entropy.

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
Auth0 PhpApplication
Affected:>= 8.0.0, < 8.19.0

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Locate Auth0-PHP SDK installation
    Search for the auth0/auth0-php package in your project's vendor directory, composer.json require/require-dev section, or lock file. Common paths: vendor/auth0/auth0-php/ or check composer show auth0/auth0-php
    Affected if The SDK is present in the project dependencies
  2. Determine installed SDK version
    Run 'composer show auth0/auth0-php' or inspect the version field in composer.lock for the auth0/auth0-php entry
    Affected if Version is 8.0.0 through 8.19.0 (inclusive)
  3. Verify cookie-based session configuration
    Inspect your application's Auth0 configuration for cookie_session or similar settings. Check if the SDK's SessionHandler or CookieHandler classes are being used. Look for 'cookie' in Auth0 client configuration files or environment variables.
    Affected if Cookie-based sessions are enabled and Auth0 SDK handles cookie encryption for session data
  4. Confirm SDK usage in authentication flow
    Search codebase for uses of Auth0\SDK\Auth0 class or related session/cookie handling. Check entry points (index.php, app bootstrap) where Auth0 SDK is instantiated for login/logout flows.
    Affected if The SDK is actively used to handle user authentication sessions

You are affected if your installed Auth0-PHP SDK version is 8.0.0 through 8.19.0 AND your application uses cookie-based sessions handled by the Auth0 SDK for authentication.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 8.19.0 or later
Fixed in 8.19.0
Interim mitigation

Upgrade the Auth0-PHP SDK to version 8.19.0 or later to obtain the patched encryption with proper entropy.

Recommended fix High confidence

8.19.0

  1. Identify the current version of auth0-php in your project (e.g., check composer.json or composer.lock)
  2. Run 'composer require auth0/auth0-php:8.19.0' or 'composer update auth0/auth0-php' to upgrade to the patched version
  3. Verify the upgrade completed successfully by checking the installed version
  4. Test your application's authentication flow to ensure the SDK still functions correctly after the upgrade
  5. Clear any cached session cookies that may have been created with the vulnerable encryption

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Auth0 Php Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-34236 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data