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Deserialization of Untrusted DataWeakness · CWE-502

CVE-2026-57621

CRITICAL · 9.8 CVSS v3.1 Published 2026-07-02
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 7 weeks old

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 Booktics <= 1.0.21 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 Booktics plugin versions up to 1.0.21 allows remote attackers to inject malicious PHP objects through unserialization of user-controlled input without proper sanitization. This can lead to remote code execution, file inclusion, or other attacks depending on available magic methods in the application context.

MitigationUpgrade to a patched version of Booktics if available; otherwise, disable the plugin until a fix is released. As a temporary measure, restrict access to the affected endpoints at the web server level if possible.

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. Confirm Booktics plugin is installed
    Locate the Booktics plugin directory in your CMS (commonly in wp-content/plugins/booktics or similar). If using a different CMS/platform, search for any directory or file containing 'booktics' in the name.
    Affected if The Booktics plugin directory exists on the server.
  2. Determine installed Booktics version
    Examine the main plugin file for a version header (typically found in the plugin's main PHP file as 'Version: x.x.x' or in a version.php / readme.txt file within the plugin directory). Compare the version number to the affected range (versions up to and including 1.0.21).
    Affected if The installed version is 1.0.21 or lower.
  3. Identify vulnerable unserialize calls
    Search the plugin source code for instances of unserialize() function being called without prior sanitization. Focus on files that process user input from request parameters, POST data, or cookies. Look for patterns like unserialize($_POST['...']) or unserialize($_COOKIE['...']).
    Affected if Code contains unserialize() calls operating directly on user-controlled input without sanitization functions like sanitize_text_field.
  4. Verify endpoint accessibility
    Identify PHP scripts in the Booktics plugin that contain the vulnerable unserialize logic. Check if these scripts are accessible without authentication (do not require login, API keys, or tokens). Attempt to access these endpoints externally or review access control configuration.
    Affected if The endpoints processing unserialized user input are reachable without authentication.

You are affected if the Booktics plugin version is 1.0.21 or lower AND the plugin contains unserialize() calls on unauthenticated user input that are publicly accessible.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to a patched version of Booktics if available; otherwise, disable the plugin until a fix is released. As a temporary measure, restrict access to the affected endpoints at the web server level if possible.

Recommended fix Moderate confidence

Booktics 1.0.22 or latest stable release

  1. 1. Back up your current Booktics installation and database before making any changes.
  2. 2. Download the latest version of Booktics from the official source or your trusted package manager.
  3. 3. Replace the existing Booktics files with the new version, preserving your configuration and data files if required.
  4. 4. Verify that the new version is 1.0.22 or later.
  5. 5. Test critical functionalities (user authentication, booking flows, admin panel) to ensure the upgrade did not break existing features.
  6. 6. Monitor application logs for any errors or unusual activity following the upgrade.
Caveat Review release notes for any configuration or feature changes between 1.0.21 and the new version

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

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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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-2026-57621 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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