Deserialization of Untrusted DataWeakness · CWE-502

CVE-2026-40755

HIGH · 8.1 CVSS v3.1 Published 2026-06-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
90/100
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
Unauthenticated PHP Object Injection in TechLink <= 1.3 versions.

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 · moderate confidence

This is an unauthenticated PHP Object Injection vulnerability in TechLink version 1.3 and earlier. PHP Object Injection occurs when untrusted serialized data is deserialized without proper validation, potentially allowing attackers to manipulate PHP object instantiation to achieve code execution, file operations, or other malicious actions depending on available 'gadget chains' in the application and its libraries.

MitigationUpgrade to a patched version of TechLink if available; otherwise, disable PHP deserialization of user input, implement strict whitelist-based input validation, and consider deploying a WAF as a temporary compensating control.

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
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:H/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 TechLink installation and determine version
    Search web root directories for TechLink folder, then check version.php, README, or composer.json for version number
    Affected if Installed version is 1.3 or lower, or version cannot be determined but TechLink is present
  2. Identify PHP files containing deserialization functions
    Search the codebase for 'unserialize' function calls using grep or similar: grep -r "unserialize" /path/to/techlink/
    Affected if Any unserialize() calls exist that process input without validation
  3. Verify if user input reaches deserialization
    Review the unserialize() calls found and trace whether $_GET, $_POST, $_COOKIE, or similar user-supplied data is passed to them
    Affected if User-controlled data is passed directly to unserialize() without sanitization
  4. Check for exposed endpoints accepting serialized data
    Review routing files and form handlers to identify endpoints that accept and process serialized PHP data from requests
    Affected if Endpoints accept serialized data from unauthenticated users

If TechLink version 1.3 or below is installed AND the application contains unserialize() calls processing unauthenticated user input, the environment is affected by this vulnerability.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to a patched version of TechLink if available; otherwise, disable PHP deserialization of user input, implement strict whitelist-based input validation, and consider deploying a WAF as a temporary compensating control.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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Scan for this in your stack

Free · runs locally
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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-2026-40755 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
  • No weaponised exploit code, or anything meant to cause harm
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