CVE-2026-8883: The Global Body Mass Index Calculator plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'gbmicalc' shortcode in versions up to...

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.

Metrics

CVSS 3.1

6.4/10

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

EPSS Probability

0.19%

8.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

References

Timeline

Published: Jun 9, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-8883?

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.

How severe is CVE-2026-8883?

CVE-2026-8883 has a CVSS score of 6.4/10 (MEDIUM severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.

How do I fix CVE-2026-8883?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.