CVE-2025-31919
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 · uneditedDeserialization of Untrusted Data vulnerability in themeton Spare allows Object Injection. This issue affects Spare: from n/a through 1.7.
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 confidenceA deserialization vulnerability in themeton Spare theme versions up to 1.7 allows unauthenticated attackers to inject PHP objects by supplying malicious serialized data. This object injection can lead to arbitrary code execution, file inclusion, or database manipulation depending on available magic methods in the application context.
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 checksWork through these to decide whether this CVE applies to you.
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Locate the Spare theme installationSearch the web server's themes directory (typically /wp-content/themes/) for a folder named 'spare', 'Spare', or similar. Verify the theme is actively installed in the WordPress site.Affected if The Spare theme by Themeton is present in the themes directory and is the active or installed theme.
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Determine the installed theme versionOpen the theme's style.css file in the Spare theme folder and look for the 'Version:' comment in the file header. Alternatively, check theme.json or version.php if present.Affected if The version number is 1.7 or lower (e.g., 1.7, 1.6, 1.5, etc.).
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Identify the vulnerable unserialize callSearch the theme's PHP files for the presence of 'unserialize()' function calls, particularly in files that handle user input (e.g., AJAX handlers, shortcode files, or template files). Common locations include functions.php, class-*.php, or ajax*.php files within the theme folder.Affected if Code contains an unserialize() call that processes data from $_GET, $_POST, $_REQUEST, or cookie values without prior sanitization.
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Verify user input reaches the deserialization pointExamine the code flow around the unserialize() call to determine if attacker-controllable parameters (from URL parameters, form submissions, or headers) can be passed directly to the unserialize function. Check if any filters or validation exist before the unserialize call.Affected if User-supplied data can reach the unserialize() function without strict validation or is stored and later unserialized without verification.
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Check for known magic methods in the themeSearch the theme and any included plugins/classes for PHP magic methods like __wakeup, __destruct, __toString, or __get that could be chained with the object injection for code execution. Review all class definitions within the theme.Affected if Classes with dangerous magic methods exist in the application context and could be invoked via the injected PHP object.
The environment is affected if the Themeton Spare theme version 1.7 or below is installed and the vulnerable unserialize() code path is reachable with user-controlled input.
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 dataReplace PHP unserialize() with safer alternatives like JSON encoding, implement strict allowlist validation if deserialization is required, and upgrade to the latest theme version when available.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-31919 — 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-2025-31919 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
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