PT-2026-34299 · WordPress · Bread & Butter

Athiwat Tiprasaharn · Published 2026-04-22 · Updated 2026-05-01 · CVE-2026-4279

Positive Technologies (AI Summary)

CVSS v3.1

6.4

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Bread & Butter versions prior to 8.2.0.26

Description Stored Cross-Site Scripting is possible via the 'breadbutter-customevent-button' shortcode. The customEventShortCodeButton() function fails to apply proper input sanitization and output escaping on the event shortcode attribute, directly interpolating the value into a JavaScript string within an onclick HTML attribute. This allows authenticated attackers with Contributor-level access and above to inject arbitrary web scripts that execute when a user clicks the injected button.

Recommendations Update to a version newer than 8.2.0.25.

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-4279

Affected Products

Bread & Butter

References · 9

• https://nvd.nist.gov/vuln/detail/CVE-2026-4279 · Security Note
• https://reddit.com/r/StopBadBots/comments/1t0qbbs/critical_alert_20_unpatched_wordpress · Reddit Post
• https://plugins.trac.wordpress.org/browser/bread-butter/tags/8.2.0.25/src/Base/Shortcode.php#L380 · Note
• https://plugins.trac.wordpress.org/browser/bread-butter/tags/8.2.0.25/src/Base/Shortcode.php#L364 · Note
• https://plugins.trac.wordpress.org/browser/bread-butter/trunk/src/Base/Shortcode.php#L364 · Note
• https://twitter.com/CVEnew/status/2047428142105801038 · Twitter Post
• https://plugins.trac.wordpress.org/browser/bread-butter/trunk/src/Base/Shortcode.php#L380 · Note
• https://twitter.com/VulmonFeeds/status/2046920029736739182 · Twitter Post
• https://wordfence.com/threat-intel/vulnerabilities/id/0728b42b-5ec7-46a2-a9a5-3316107e9324?source=cve · Note