CVE-2026-8891CWE-79

BitForm <= 1.1.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes

Medium · published May 27, 2026

CVSS v3.1
6.4
EPSS
0%
Percentile
25.1
In the wild
Unconfirmed
What it is

The BitForm plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'bitform' shortcode in versions up to, and including, 1.1.0. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes ('width' and 'height') in the Shortcode::shortcode() function, which are interpolated directly into the 'style' attribute of an <iframe> element. 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.

The record
Technical detail
CVSS v3.1
6.4 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00331 · 25.1th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-05-27T05:31Z
EPSS history
Timeline
  • 27 MAY 05:31Z
    BitForm <= 1.1.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes
    cvelistv5