CVE-2026-4329Blackhole for Bad Bots <= 3.8 - Unauthenticated Stored Cross-Site Scripting via User-Agent HTTP Header
- 7.2HighCVSS base score
- 0.33%Exploitation in 30 daysEPSS · top 74% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By Wordfence
- 9 days later
· 9 days later
Published
- 13 days later
· 13 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| WordfenceCNA (assigner) | 3.1 | High7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
| NVDNVD · Deferred | 3.1 | High7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.33% · top 74% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.2.
Affected products
specialk · Blackhole for Bad Bots
- affected ≤ 3.8
References
References12
- https://www.wordfence.com/threat-intel/vulnerabilities/id/a71992e2-fdac-4e89-8867-4b771d9b4374?source=cve (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/trunk/inc/badbots-register.php#L75 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/trunk/inc/badbots-register.php#L85 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/trunk/inc/badbots-register.php#L79 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/badbots-register.php#L79 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/badbots-register.php#L85 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/badbots-register.php#L75 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/trunk/inc/blackhole-helpers.php#L22 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/blackhole-helpers.php#L22 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/trunk/inc/blackhole-core.php#L180 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/blackhole-core.php#L180 (opens in a new tab)
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3487350%40blackhole-bad-bots&new=3487350%40blackhole-bad-bots&sfp_email=&sfph_mail= (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-16102 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-4329)Record last updated .