Deserialization of Untrusted DataWeakness · CWE-502

CVE-2025-39551

CRITICAL · 9.8 CVSS v3.1 Published 2025-04-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
Deserialization of Untrusted Data vulnerability in Mahmudul Hasan Arif FluentBoards fluent-boards allows Object Injection.This issue affects FluentBoards: from n/a through <= 1.47.

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

FluentBoards versions through 1.47 contain a deserialization vulnerability where untrusted data is deserialized without proper validation, allowing an attacker to inject malicious objects. This type of flaw can lead to remote code execution or other serious impacts given the critical CVSS score of 9.8.

MitigationUpgrade FluentBoards to the latest patched version. If no patch is available, review and sanitize all deserialization points in the application code, implement strict allowlist validation for deserialized objects, and consider disabling PHP deserialization functions if applicable.

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 FluentBoards installation
    Locate FluentBoards application files in your web root or application directory. Check for the presence of fluentboards-specific directories or files such as composer.json, config files, or the main application entry point.
    Affected if FluentBoards software is present in the environment
  2. Determine installed FluentBoards version
    Check the version by reviewing composer.json for the 'version' field, examining a VERSION file if present, or accessing the admin panel/version information page if available.
    Affected if The installed version is 1.47 or lower (through 1.47)
  3. Verify PHP deserialization is in use
    Search the application source code for PHP deserialization functions such as unserialize(), file_get_contents() with deserialization, or any custom deserialization logic handling untrusted data.
    Affected if The application uses unserialize() or similar functions on untrusted input
  4. Check application configuration
    Review application configuration files for settings related to data import, serialization, or object handling that may accept and deserialize user-supplied data.
    Affected if Configuration allows deserialization of user-provided or external data without validation

If FluentBoards version 1.47 or lower is deployed and the application performs deserialization on untrusted data, the environment is vulnerable to CVE-2025-39551.

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 FluentBoards to the latest patched version. If no patch is available, review and sanitize all deserialization points in the application code, implement strict allowlist validation for deserialized objects, and consider disabling PHP deserialization functions if applicable.

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
dbcve dependency scanner

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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-2025-39551 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
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