CVE-2026-97275

Executive Summary

CVE-2026-97275 is an Improper Validation of Specified Quantity in Input (CWE-1284) vulnerability affecting the VillaTheme BuildKit – Product Builder for WooCommerce – Custom PC Builder plugin for WordPress, versions up to and including 1.0.28. Due to a failure to properly validate input quantities, an unauthenticated remote attacker can manipulate input data submitted through the plugin, resulting in limited integrity impact. The vulnerability carries a CVSS v3.1 base score of 5.3 (Medium severity) and has no confirmed public exploit or patch at the time of reporting.

Technical Analysis

The vulnerability resides in the BuildKit – Product Builder for WooCommerce – Custom PC Builder WordPress plugin, a tool that allows site owners to offer configurable product builds (e.g., custom PC configurations) within WooCommerce. The root cause is classified as CWE-1284: Improper Validation of Specified Quantity in Input. This weakness occurs when an application accepts a quantity value from user-controlled input but fails to validate that the value is within expected bounds, of the correct type, or semantically valid before processing it.

In the context of this plugin, “quantity” likely refers to user-supplied numeric values used to specify component counts, build quantities, or configuration parameters during a product-building workflow. Because the plugin does not adequately validate these values, an attacker can submit crafted input that deviates from the expected range or format. The NVD description explicitly states that the flaw “allows Input Data Manipulation,” which indicates the primary consequence is the ability to alter the data that the application processes or stores, rather than achieving code execution, privilege escalation, or denial of service.

The attack surface is network-accessible (AV:N) and requires no authentication (PR:N) or user interaction (UI:N), meaning any remote client capable of reaching the WordPress site can attempt to exploit it. The CVSS vector (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N) confirms that there is no impact to confidentiality or availability; only integrity is affected, and only to a limited degree. This aligns with a scenario where manipulated quantity values could alter cart contents, pricing calculations, or inventory-related data, but would not grant unauthorized access to sensitive information or disrupt service availability.

No specific function names, parameter names, or file paths are disclosed in the NVD description or CNA title. Therefore, the exact code-level mechanism cannot be detailed without speculation. The vulnerability class, however, is well understood: improper input validation of numeric quantities can lead to logic bypasses, data corruption, or manipulation of business logic that relies on those values.

Affected product versions are all releases from the initial version through 1.0.28, as indicated by the “from n/a through 1.0.28” range. There is no evidence of a patch in any tracked source, and patch confidence is rated 0/4 (UNPATCHED).

Exploitation Scenarios

No public proof-of-concept or exploit code is available for this CVE. The following exploitation scenario is inferred strictly from the vulnerability class (CWE-1284) and the NVD description; it does not rely on invented implementation details.

1. Reconnaissance / Target Identification: An attacker scans for WordPress sites running the BuildKit – Product Builder for WooCommerce – Custom PC Builder plugin. This can be done via Shodan dorks targeting page content related to the plugin (e.g., “BuildKit” or “Custom PC Builder”) or by fingerprinting the plugin’s public-facing assets. Sites with WooCommerce and custom product builder functionality are the primary targets.

2. Triggering the Flaw Class: The attacker interacts with the plugin’s product-building interface, which accepts quantity inputs from users. Because the plugin fails to properly validate the specified quantity, the attacker submits a crafted value — such as an out-of-range number, a negative value, or a non-numeric string — where a valid quantity is expected. The exact input vector (e.g., a form field, AJAX request, or REST parameter) is not disclosed, but the vulnerability class implies that any input path feeding quantity data into the plugin is potentially affected.

3. Payload / Execution Method: At the vulnerability-class level, the payload is a malformed or unexpected quantity value. The attacker does not need to inject code or exploit a memory corruption bug; instead, they manipulate the data that the application processes. For example, submitting an excessively large quantity or a negative quantity could cause the plugin to accept and store incorrect values, leading to manipulated build configurations, altered pricing, or inconsistent cart data.

4. Post-Exploitation Impact: The impact is limited to integrity (I:L). The attacker can manipulate input data, potentially resulting in incorrect product configurations, tampered order details, or business logic bypasses. There is no confidentiality or availability impact, so the attacker cannot read sensitive data or crash the service. The practical effect is data manipulation that may require manual correction by site administrators or may be leveraged in further social engineering or fraud scenarios.

Impact Assessment

The CVSS v3.1 base score of 5.3 reflects a Medium severity vulnerability with the following subscores: Attack Vector: Network, Attack Complexity: Low, Privileges Required: None, User Interaction: None, Scope: Unchanged, Confidentiality: None, Integrity: Low, Availability: None. This means exploitation is straightforward for a remote attacker and requires no special conditions, but the resulting impact is constrained to limited data manipulation.

Business impact includes potential corruption of product configuration data, incorrect order quantities, or manipulation of custom PC build specifications. For e-commerce sites, this could lead to customer disputes, order fulfillment errors, or reputational damage if manipulated builds are processed. However, because there is no confidentiality or availability impact, the blast radius is limited to data integrity within the plugin’s scope. There is no evidence of lateral movement, privilege escalation, or server compromise. The vulnerability affects any WordPress installation running the vulnerable plugin version (<= 1.0.28), regardless of site size, but the severity for individual sites depends on how critical accurate product configuration data is to their operations.

Detection Guidance

Sigma Rule

title: Potential CVE-2026-97275 Exploitation Attempt - WooCommerce Product Builder Quantity Manipulation
id: 8f4a2b1e-7c3d-4e5f-9a6b-1c2d3e4f5a6b
status: experimental
description: Detects suspicious HTTP requests targeting the BuildKit Product Builder plugin with malformed quantity parameters.
author: Threat Intelligence
date: 2026-01-01
logsource:
  category: webserver
  product: apache
  service: access_combined
detection:
  selection_uri:
    cs-uri-query|contains:
      - 'quantity='
      - 'qty='
      - 'product_builder'
      - 'buildkit'
  selection_payload:
    cs-uri-query|re:
      - '(?i)(quantity|qty)=\d{10,}'  # excessive numeric value
      - '(?i)(quantity|qty)=-'        # negative value
      - '(?i)(quantity|qty)=[^0-9]'   # non-numeric
  condition: selection_uri and selection_payload
falsepositives:
  - Legitimate users entering large quantities
  - Custom themes with different parameter names
level: medium
tags:
  - attack.t1190
  - cve.2026.97275

YARA Rule

rule CVE_2026_97275_WooCommerce_Quantity_Manipulation
{
    meta:
        description = "Detects HTTP requests attempting to exploit CVE-2026-97275 in BuildKit Product Builder plugin"
        author = "Threat Intelligence"
        date = "2026-01-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-97275"
        severity = "medium"

    strings:
        $plugin1 = "woo-product-builder" ascii wide nocase
        $plugin2 = "buildkit" ascii wide nocase
        $param1 = "quantity=" ascii wide nocase
        $param2 = "qty=" ascii wide nocase
        $susp1 = /quantity=-[0-9]+/ ascii wide
        $susp2 = /qty=-[0-9]+/ ascii wide
        $susp3 = /quantity=[0-9]{10,}/ ascii wide
        $susp4 = /qty=[0-9]{10,}/ ascii wide

    condition:
        (any of ($plugin*)) and (any of ($param*)) and (any of ($susp*))
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-97275 WooCommerce Product Builder Quantity Manipulation Attempt"; flow:to_server,established; content:"quantity="; http_uri; nocase; pcre:"/(quantity|qty)=(-[0-9]+|[0-9]{10,})/iU"; reference:cve,2026-97275; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-97275; classtype:attempted-recon; sid:9000001; rev:1;)

Elastic Detection

sequence by source.ip with maxspan=5s
  [ network where network.protocol == "http" and
      http.request.method == "GET" and
      url.query contains "quantity=" and
      (url.query regex ".*(quantity|qty)=-\\d+.*" or url.query regex ".*(quantity|qty)=\\d{10,}.*") ]
  [ network where network.protocol == "http" and
      url.query contains "product_builder" or url.query contains "buildkit" ]

Splunk SPL Query

index=web sourcetype=access_combined
| search (uri_query="*quantity=*" OR uri_query="*qty=*")
| regex uri_query="(?i)(quantity|qty)=(-[0-9]+|[0-9]{10,})"
| eval risk="CVE-2026-97275 potential exploit attempt"
| table _time, clientip, method, uri_path, uri_query, status, risk
| sort - _time

Wazuh OSSEC Rule

<group name="web,wordpress,cve-2026-97275">
  <rule id="100500" level="8">
    <if_sid>31100</if_sid>
    <field name="url">quantity=</field>
    <description>CVE-2026-97275: Possible BuildKit Product Builder quantity manipulation attempt</description>
    <regex>(?i)(quantity|qty)=(-[0-9]+|[0-9]{10,})</regex>
    <mitre>
      <id>T1190</id>
    </mitre>
    <group>cve_2026_97275,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence is 0/4 (UNPATCHED — no patch evidence from any tracked source). No vendor fix or workaround is currently available.

1. Immediate Mitigations:

   • Disable or remove the BuildKit – Product Builder for WooCommerce – Custom PC Builder plugin if it is not business-critical.
   • If the plugin must remain active, deploy a Web Application Firewall (WAF) rule to block requests containing suspicious quantity parameters (e.g., negative values or excessively large integers) targeting the plugin’s endpoints.
   • Implement virtual patching via a WAF or reverse proxy to enforce strict numeric validation on quantity inputs before they reach the application.
   • Restrict access to the plugin’s front-end functionality to authenticated users only, if feasible, to reduce the unauthenticated attack surface.

2. Patch/Upgrade Steps:

   • Monitor the vendor’s official channels (VillaTheme website and WordPress plugin repository) for a security update. As of this report, no patch exists. Once a patched version is released (expected > 1.0.28), upgrade immediately.
   • Subscribe to the NVD entry for CVE-2026-97275 and WordPress security mailing lists for patch announcements.

3. Long-Term Hardening:

   • Enforce strict server-side input validation for all numeric fields, including range checks and type validation.
   • Conduct a security review of all custom WooCommerce extensions, particularly those handling user-supplied quantities or pricing data.
   • Implement logging and alerting for anomalous quantity values in web requests to detect exploitation attempts early.
   • Apply the principle of least privilege to plugin and theme code, ensuring that user input cannot alter critical business logic.
   • Regularly audit installed plugins for vulnerabilities and remove unused or unsupported components.

References

• NVD – CVE-2026-97275: https://nvd.nist.gov/vuln/detail/CVE-2026-97275
• CWE-1284: Improper Validation of Specified Quantity in Input: https://cwe.mitre.org/data/definitions/1284.html
• VillaTheme – BuildKit Product Builder for WooCommerce: https://villatheme.com/
• WordPress Plugin Repository – BuildKit Product Builder: https://wordpress.org/plugins/woo-product-builder/
• CISA Known Exploited Vulnerabilities Catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog (CVE-2026-97275 is not currently listed)
• No known threat actor campaigns or exploit-in-the-wild evidence have been observed for this CVE as of the report date.