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CWE-184Weakness · CWE-184

CVE-2026-34415

CRITICAL · 9.8 CVSS v3.1 Published 2026-04-22
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
Xerte Online Toolkits versions 3.15 and earlier contain an incomplete input validation vulnerability in the elFinder connector endpoint that fails to block PHP-executable extensions .php4 due to an incorrect regex pattern. Unauthenticated attackers can exploit this flaw combined with authentication bypass and path traversal vulnerabilities to upload malicious PHP code, rename it with a .php4 extension, and execute arbitrary operating system commands on the server.

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

Xerte Online Toolkits versions 3.15 and earlier have an incomplete input validation vulnerability in the elFinder connector endpoint. The regex pattern used to block executable PHP extensions fails to include .php4, allowing attackers to bypass the filter. Combined with separate authentication bypass and path traversal flaws, unauthenticated attackers can upload malicious PHP code, rename it with a .php4 extension, and achieve remote code execution.

MitigationApply vendor patches when available and immediately restrict or disable the elFinder connector endpoint until the regex pattern is corrected to block all executable PHP variants (.php, .php4, .php5, .phtml, etc.), alongside remediating the authentication bypass and path traversal vulnerabilities.

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. Identify Xerte Online Toolkits installation and version
    Check the version.php or version file in the Xerte installation directory, or look at the login page footer which typically displays the version number
    Affected if The installed version is 3.15 or any version earlier than the patched release
  2. Locate and inspect the elFinder connector configuration
    Find the elFinder connector PHP file (typically connector.php or similar in a modules/elfinder or libraries/elfinder path) and examine the file extension validation regex pattern used for uploads
    Affected if The regex pattern allows .php4 extensions or does not explicitly block executable PHP-related extensions (.php, .php4, .php5, .phtml, etc.)
  3. Verify elFinder connector is exposed without authentication
    Attempt to access the elFinder connector endpoint directly without logging in, or inspect the authentication checks in the connector code to determine if unauthenticated access is possible
    Affected if The elFinder connector endpoint is accessible without valid authentication
  4. Check for path traversal protection in file operations
    Review the elFinder connector code for path traversal safeguards when handling file move/rename operations, particularly looking for proper validation of user-supplied paths
    Affected if The connector lacks proper path traversal validation allowing attackers to manipulate file paths outside intended directories
  5. Determine if file rename functionality is available to unauthenticated users
    Test or audit whether the elFinder API permits file rename operations without authentication, or examine the permissions configuration
    Affected if Unauthenticated users can rename uploaded files to executable extensions like .php4

A defender is affected if Xerte Online Toolkits version 3.15 or earlier is running with the elFinder connector exposed and the extension validation regex does not block .php4 and other PHP variants.

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

Apply vendor patches when available and immediately restrict or disable the elFinder connector endpoint until the regex pattern is corrected to block all executable PHP variants (.php, .php4, .php5, .phtml, etc.), alongside remediating the authentication bypass and path traversal vulnerabilities.

Recommended fix Moderate confidence

Upgrade to Xerte Online Toolkits version greater than 3.15 when released

  1. Review the vendor patch at https://github.com/thexerteproject/xerteonlinetoolkits/commit/02661be88cc369325ea01b508086bde7fbfec805 to understand the regex correction for blocking .php4 extensions
  2. Apply the patch to the elFinder connector endpoint in the Xerte Online Toolkits installation
  3. Verify that .php4 files can no longer be uploaded through the elFinder connector
  4. Confirm the authentication bypass and path traversal components are also addressed if the patch covers those vulnerabilities

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

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
Get the patch applied

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

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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-2026-34415 in production — separate from our analysis above.

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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
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