CVE-2026-4279
The Bread & Butter plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'breadbutter-customevent-button' shortcode in all versions up to, and including, 8.2.0.25.
Does this matter?
Lower severity and a low EPSS score (0.24%). Track it; it rarely justifies an emergency change on its own.
Description
The Bread & Butter plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'breadbutter-customevent-button' shortcode in all versions up to, and including, 8.2.0.25. This is due to insufficient input sanitization and output escaping on the 'event' shortcode attribute. The customEventShortCodeButton() function takes the 'event' attribute value and directly interpolates it into a JavaScript string within an onclick HTML attribute without applying esc_attr() or esc_js(). Notably, the sister function customEventShortCode() properly uses esc_js() for the same attribute, but this was omitted in the button variant. 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 the page and clicks the injected button.
- CVSS 3.1
- 6.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- EPSS
- 0.24% probability · 15th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Source
- security@wordfence.com
References
- https://plugins.trac.wordpress.org/browser/bread-butter/tags/8.2.0.25/src/Base/Shortcode.php#L364
- https://plugins.trac.wordpress.org/browser/bread-butter/tags/8.2.0.25/src/Base/Shortcode.php#L380
- https://plugins.trac.wordpress.org/browser/bread-butter/trunk/src/Base/Shortcode.php#L364
- https://plugins.trac.wordpress.org/browser/bread-butter/trunk/src/Base/Shortcode.php#L380
- https://www.wordfence.com/threat-intel/vulnerabilities/id/0728b42b-5ec7-46a2-a9a5-3316107e9324?source=cve
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.