CVE-2026-8891 json
BitForm <= 1.1.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes
published 2026-05-27 5 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-32077
- cvss
- 6.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 9%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 5 mo ago
Exploit prediction
0.19% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
Affected products
- bitform BitForm – Data management solution for WordPress
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
- Technology feeds
References
- wordfence.com /threat-intel/vulnerabilities/id/71167dec-38ec-4eb3-8fab-25eca0f8b071?source=cve
- plugins.trac.wordpress.org /browser/bitform/tags/1.1.0/Common/Shortcode.php#L17
- plugins.trac.wordpress.org /browser/bitform/tags/1.1.0/Common/Shortcode.php#L13
- plugins.trac.wordpress.org /browser/bitform/tags/1.1.0/index.php#L54
Sources
- CVE List CVE-2026-8891
- NVD CVE-2026-8891
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.