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Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-8883

MEDIUM · 6.4 CVSS v3.1 Published 2026-06-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
Remotely reachable 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
The Global Body Mass Index Calculator plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'gbmicalc' shortcode in versions up to, and including, 1.2. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes in the GBMI_Calc_Widget::widget() function. Shortcode attributes are extracted directly into local variables via @extract($args) and then echoed unescaped into an HTML style attribute (height/width) and HTML body context (title), allowing attribute-breakout payloads. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

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 confidence

The Global Body Mass Index Calculator WordPress plugin uses @extract($args) to import shortcode attributes directly into local variables, then echoes these values unescaped into HTML style attributes (height/width) and body content (title). This allows attribute-breakout XSS where an attacker with contributor+ access can inject malicious JavaScript via crafted shortcode attributes.

MitigationReplace @extract($args) with explicit attribute retrieval, then sanitize all output using esc_attr() for HTML attributes and esc_html() for text content before echoing into the HTML 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
Low
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

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. Verify plugin version
    In WordPress admin, go to Plugins > Installed Plugins and find 'Global Body Mass Index Calculator'. Check the version number listed there, or inspect the plugin header in /wp-content/plugins/global-bmi-calculator/ or similar folder path.
    Affected if The installed version is 1.2 or lower (versions up to 1.2 are affected)
  2. Confirm shortcode is in use
    Search your WordPress posts, pages, and widgets for the '[gbmicalc]' shortcode using admin search or by querying the wp_posts table for post_content containing 'gbmicalc'.
    Affected if The shortcode [gbmicalc] is present in any published content
  3. Identify contributor-level users
    Navigate to Users > All Users in WordPress admin, or query wp_users and wp_usermeta to list accounts with the 'contributor' role.
    Affected if Any user account with contributor role or higher exists (attackers need contributor access to exploit)
  4. Inspect vulnerable widget code
    Locate the file containing GBMI_Calc_Widget::widget() - typically in the plugin directory. Examine the code for use of @extract($args) followed by unescaped echo of $args variables into HTML style attributes or body content.
    Affected if The widget function contains @extract($args) with unescaped output of shortcode attributes in height/width style tags or title field
  5. Check for recent shortcode modifications
    Review WordPress post revisions or audit logs for recent creation/modification of content containing [gbmicalc], especially by contributor-level users.
    Affected if Suspicious or unexpected [gbmicalc] shortcode entries appear in recent content

Your environment is affected if the Global Body Mass Index Calculator plugin version 1.2 or lower is installed, the [gbmicalc] shortcode is in use, and users with contributor-level access exist who could inject malicious attributes.

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

Replace @extract($args) with explicit attribute retrieval, then sanitize all output using esc_attr() for HTML attributes and esc_html() for text content before echoing into the HTML context.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
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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-2026-8883 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
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  • Version or environment caveats, and links to real fixes
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