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Code InjectionWeakness · CWE-94

CVE-2026-39918

CRITICAL · 9.8 CVSS v3.1 Published 2026-04-20
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

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
Vvveb prior to 1.0.8.1 contains a code injection vulnerability in the installation endpoint where the subdir POST parameter is written unsanitized into the env.php configuration file without escaping or validation. Attackers can inject arbitrary PHP code by breaking out of the string context in the define statement to achieve unauthenticated remote code execution as the web server user.

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

Vvveb before 1.0.8.1 has a code injection vulnerability in its installation endpoint where the subdir POST parameter is written directly to the env.php configuration file without sanitization, escaping, or validation. Attackers can break out of the string context in the define statement to inject arbitrary PHP code and achieve unauthenticated remote code execution as the web server user.

MitigationUpgrade to Vvveb 1.0.8.1 or later which implements proper input sanitization and validation for the subdir parameter before writing to configuration files.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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. Verify Vvveb installation exists
    Look for the presence of Vvveb by checking for characteristic files such as env.php in the web root or a vvveb-specific directory structure.
    Affected if No Vvveb installation found means this CVE does not apply.
  2. Check installed Vvveb version
    Locate and read the version file or header files within the Vvveb installation. Compare the version number against the affected range: versions prior to 1.0.8.1 are vulnerable.
    Affected if Installed version is before 1.0.8.1.
  3. Confirm installation endpoint is present
    Check whether the installation directory or installer script still exists in the web-accessible path. Look for installation-related PHP files or directories that are typically removed after setup.
    Affected if The installation endpoint or installer files remain accessible on the system.
  4. Inspect env.php for injected code
    Open the env.php configuration file and examine its contents. Look for unexpected PHP code, suspicious define() statements, or content that does not match expected configuration format.
    Affected if env.php contains malformed PHP code, unexpected define() statements, or suspicious characters indicating injection.

You are affected if Vvveb is installed with a version before 1.0.8.1 and the installation endpoint is still accessible or the env.php file shows signs of code injection.

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
Patch available Apply the vendor patch
Vendor patch github.com →
Interim mitigation

Upgrade to Vvveb 1.0.8.1 or later which implements proper input sanitization and validation for the subdir parameter before writing to configuration files.

Recommended fix High confidence

Vvveb 1.0.8.1

  1. 1. Back up the entire Vvveb installation directory and database before making any changes
  2. 2. Download Vvveb version 1.0.8.1 from the official GitHub repository or release page
  3. 3. Replace the existing installation files with the new version 1.0.8.1 files
  4. 4. Verify that the installation endpoint now properly sanitizes the subdir POST parameter before writing to env.php
  5. 5. After upgrade, test that the application functions normally and the installation process works correctly
  6. 6. Remove the /install directory if it still exists after installation to prevent future abuse

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

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,750
Get the patch applied

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

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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-2026-39918 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