CVE-2026-39539
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 · uneditedUnauthenticated PHP Object Injection in Alloggio - Hotel Booking <= 2.1.2 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 · high confidenceUnauthenticated PHP Object Injection vulnerability in the Alloggio WordPress Hotel Booking plugin versions 2.1.2 and below. The plugin deserializes untrusted user input without proper validation, allowing remote attackers to inject malicious PHP objects and potentially execute arbitrary code via gadget chains in the application or connected libraries.
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 checksWork through these to decide whether this CVE applies to you.
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Check installed plugin versionNavigate to WordPress Admin > Plugins > Installed Plugins and locate 'Alloggio - Hotel Booking' in the list. The version number is displayed under the plugin name. Alternatively, inspect the main plugin file (typically alloggio.php or similar in wp-content/plugins/alloggio/) and look for the 'Version:' header in the plugin comment block.Affected if Version number displayed is 2.1.2 or lower
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Verify plugin is activeIn WordPress Admin > Plugins, confirm the Alloggio Hotel Booking plugin shows as 'Active' (not deactivated or missing). Alternatively, query the wp_options table for the option_name 'active_plugins' and check if the plugin slug is present.Affected if Plugin is currently active on the site
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Locate vulnerable unserialize() callAccess the plugin files via FTP or file manager. Search all PHP files within the plugin directory for calls to unserialize() that process input without prior sanitization. Common patterns include: unserialize($_POST['...']), unserialize($_GET['...']), or unserialize($_REQUEST['...']). Examine files that handle form submissions, AJAX endpoints, or API callbacks.Affected if Code contains unserialize() function operating on untrusted user-supplied data without validation
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Check for unauthenticated access to vulnerable endpointReview the plugin's PHP files to identify endpoints, hooks, or actions that can be accessed without authentication (no require_login, is_user_logged_in, or capability checks). Focus on AJAX handlers (wp_ajax_* and wp_ajax_nopriv_*) and direct file includes. Verify if the vulnerable unserialize() call is reachable from these unauthenticated paths.Affected if The unserialize() call is reachable via an endpoint accessible to unauthenticated users
Your environment is affected if the Alloggio Hotel Booking plugin is active and the installed version is 2.1.2 or lower, with a reachable unserialize() call on unauthenticated input in the plugin code.
Generated from the published advisory. Verify against your own configuration.
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 dataUpgrade to a patched version of Alloggio - Hotel Booking plugin; if no patch available, disable the plugin until a fix is released. As an interim measure, verify all unserialize() calls in the plugin code and replace with json_decode() or safe serialization methods with strict input validation.
- Consultation3.0 h
- Implementation6.0 h
- Testing5.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-39539 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-39539 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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