Blackhole for Bad Bots <= 3.8 - Unauthenticated Stored Cross-Site Scripting via User-Agent HTTP Header

Summary

CVE	CVE-2026-4329
State	PUBLISHED
Assigner	Wordfence
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-03-26 05:16:40 UTC
Updated	2026-03-30 13:26:50 UTC
Description	The Blackhole for Bad Bots plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the User-Agent HTTP header in all versions up to and including 3.8. This is due to insufficient input sanitization and output escaping. The plugin uses sanitize_text_field() when capturing bot data (which strips HTML tags but does not escape HTML entities like double quotes), then stores the data via update_option(). When an administrator views the Bad Bots log page, the stored data is output directly into HTML input value attributes (lines 75-83) without esc_attr() and into HTML span content without esc_html(). This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute when an administrator views the Blackhole Bad Bots admin page.

Risk And Classification

Primary CVSS: v3.1 7.2 HIGH from [email protected]

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

EPSS: 0.001570000 probability, percentile 0.366180000 (date 2026-04-02)

Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Version	Source	Type	Score	Severity	Vector
3.1	[email protected]	Primary	7.2	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N`
3.1	CNA	DECLARED	7.2	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N`

CVSS v3.1 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

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

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	Specialk	Blackhole For Bad Bots	affected * 3.8 semver	Not specified

References

Reference	Source	Link	Tags
plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/blackhole-helpers.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/blackhole-bad-bots/trunk/inc/badbots-register.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/blackhole-bad-bots/trunk/inc/badbots-register.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/blackhole-core.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/blackhole-bad-bots/trunk/inc/blackhole-helpers.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/blackhole-bad-bots/trunk/inc/blackhole-core.php	[email protected]	plugins.trac.wordpress.org
www.wordfence.com/threat-intel/vulnerabilities/id/a71992e2-fdac-4e89-8867-4b771...	[email protected]	www.wordfence.com
plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/badbots-register.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/blackhole-bad-bots/trunk/inc/badbots-register.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/badbots-register.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/badbots-register.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/changeset	[email protected]	plugins.trac.wordpress.org
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Huynh Pham Thanh Luc (en)

Additional Advisory Data

Source	Time	Event
CNA	2026-03-17T15:25:26.000Z	Vendor Notified
CNA	2026-03-25T00:00:00.000Z	Disclosed

There are currently no legacy QID mappings associated with this CVE.