dbcve.org
Deserialization of Untrusted DataWeakness · CWE-502

CVE-2026-40754

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 Roisin <= 1.4 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

Unauthenticated PHP Object Injection vulnerability in Roisin CMS versions 1.4 and below allows remote attackers to inject malicious PHP objects by sending crafted serialized data, potentially leading to remote code execution if suitable gadget chains exist in the application or its dependencies.

MitigationUpgrade to a patched version of Roisin if available; otherwise, disable PHP unserialize() on user-supplied input and implement strict input validation or whitelist-based sanitization for all untrusted data streams.

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. Confirm Roisin CMS installation
    Locate Roisin CMS files in the web root directory. Check for the presence of index.php, admin/, or similar Roisin-specific directories and files.
    Affected if Roisin CMS is present on the server
  2. Identify installed version
    Look for a version file or check the main CMS files for a version constant/string. Common locations include a VERSION file, config file, or the main index.php entry point.
    Affected if The identified version is 1.4 or below
  3. Find unserialize() usage on user input
    Search PHP source files for calls to unserialize() function. Use grep or a similar tool: grep -r "unserialize" /path/to/roisin/ .
    Affected if The codebase contains unserialize() calls processing external input
  4. Trace input sources to unserialize() calls
    Examine each unserialize() call found to determine if $_GET, $_POST, $_COOKIE, $_REQUEST, or other user-supplied data is passed to it without sanitization.
    Affected if User-controlled data from $_GET, $_POST, $_COOKIE, or similar superglobals reaches unserialize() without validation

A user is affected if Roisin CMS version 1.4 or below is installed AND the application uses unserialize() on data originating from untrusted user input.

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 Roisin if available; otherwise, disable PHP unserialize() on user-supplied input and implement strict input validation or whitelist-based sanitization for all untrusted data streams.

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
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-40754 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2026-40754 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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